diff --git a/BroadcastApp/.idea/compiler.xml b/BroadcastApp/.idea/compiler.xml
deleted file mode 100644
index 96cc43e..0000000
--- a/BroadcastApp/.idea/compiler.xml
+++ /dev/null
@@ -1,22 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <resourceExtensions />
-    <wildcardResourcePatterns>
-      <entry name="!?*.java" />
-      <entry name="!?*.form" />
-      <entry name="!?*.class" />
-      <entry name="!?*.groovy" />
-      <entry name="!?*.scala" />
-      <entry name="!?*.flex" />
-      <entry name="!?*.kt" />
-      <entry name="!?*.clj" />
-      <entry name="!?*.aj" />
-    </wildcardResourcePatterns>
-    <annotationProcessing>
-      <profile default="true" name="Default" enabled="false">
-        <processorPath useClasspath="true" />
-      </profile>
-    </annotationProcessing>
-  </component>
-</project>
\ No newline at end of file
diff --git a/BroadcastApp/.idea/copyright/profiles_settings.xml b/BroadcastApp/.idea/copyright/profiles_settings.xml
deleted file mode 100644
index e7bedf3..0000000
--- a/BroadcastApp/.idea/copyright/profiles_settings.xml
+++ /dev/null
@@ -1,3 +0,0 @@
-<component name="CopyrightManager">
-  <settings default="" />
-</component>
\ No newline at end of file
diff --git a/BroadcastApp/.idea/encodings.xml b/BroadcastApp/.idea/encodings.xml
deleted file mode 100644
index 97626ba..0000000
--- a/BroadcastApp/.idea/encodings.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="Encoding">
-    <file url="PROJECT" charset="UTF-8" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/BroadcastApp/.idea/gradle.xml b/BroadcastApp/.idea/gradle.xml
index 7ac24c7..ac6b0ae 100644
--- a/BroadcastApp/.idea/gradle.xml
+++ b/BroadcastApp/.idea/gradle.xml
@@ -1,10 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
+        <option name="testRunner" value="PLATFORM" />
         <option name="distributionType" value="DEFAULT_WRAPPED" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
+        <option name="gradleJvm" value="1.8" />
         <option name="modules">
           <set>
             <option value="$PROJECT_DIR$" />
diff --git a/BroadcastApp/.idea/misc.xml b/BroadcastApp/.idea/misc.xml
index 9adc8c9..703e5d4 100644
--- a/BroadcastApp/.idea/misc.xml
+++ b/BroadcastApp/.idea/misc.xml
@@ -1,62 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
+  <component name="CMakeSettings">
+    <configurations>
+      <configuration PROFILE_NAME="Debug" CONFIG_NAME="Debug" />
+    </configurations>
   </component>
-  <component name="NullableNotNullManager">
-    <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
-    <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
-    <option name="myNullables">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
-        </list>
-      </value>
-    </option>
-    <option name="myNotNulls">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
-        </list>
-      </value>
-    </option>
-  </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
     <option name="id" value="Android" />
   </component>
-  <component name="masterDetails">
-    <states>
-      <state key="ProjectJDKs.UI">
-        <settings>
-          <last-edited>Android API 24 Platform</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-    </states>
-  </component>
 </project>
\ No newline at end of file
diff --git a/BroadcastApp/.idea/modules.xml b/BroadcastApp/.idea/modules.xml
index 7ddf48d..5748b40 100644
--- a/BroadcastApp/.idea/modules.xml
+++ b/BroadcastApp/.idea/modules.xml
@@ -2,8 +2,8 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/BroadcastApp.iml" filepath="$PROJECT_DIR$/BroadcastApp.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/BroadcastApp.iml" filepath="$PROJECT_DIR$/.idea/modules/BroadcastApp.iml" group="BroadcastApp" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/app/app.iml" filepath="$PROJECT_DIR$/.idea/modules/app/app.iml" group="BroadcastApp/app" />
     </modules>
   </component>
 </project>
\ No newline at end of file
diff --git a/BroadcastApp/app/build.gradle b/BroadcastApp/app/build.gradle
index eb6e23c..27afd00 100644
--- a/BroadcastApp/app/build.gradle
+++ b/BroadcastApp/app/build.gradle
@@ -1,30 +1,42 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.0"
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
+
     defaultConfig {
-        applicationId "com.example.jyheo.broadcastapp"
-        minSdkVersion 22
-        targetSdkVersion 25
+        applicationId "com.example.broadcastapp"
+        minSdkVersion 23
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
+
     buildTypes {
         release {
             minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
+
+    buildFeatures {
+        viewBinding true
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    })
-    compile 'com.android.support:appcompat-v7:25.3.0'
-    compile 'com.android.support.constraint:constraint-layout:1.0.0-beta1'
-    testCompile 'junit:junit:4.12'
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
 }
diff --git a/BroadcastApp/app/src/androidTest/java/com/example/jyheo/broadcastapp/ExampleInstrumentedTest.java b/BroadcastApp/app/src/androidTest/java/com/example/broadcastapp/ExampleInstrumentedTest.java
similarity index 81%
rename from BroadcastApp/app/src/androidTest/java/com/example/jyheo/broadcastapp/ExampleInstrumentedTest.java
rename to BroadcastApp/app/src/androidTest/java/com/example/broadcastapp/ExampleInstrumentedTest.java
index 876478f..f04488d 100644
--- a/BroadcastApp/app/src/androidTest/java/com/example/jyheo/broadcastapp/ExampleInstrumentedTest.java
+++ b/BroadcastApp/app/src/androidTest/java/com/example/broadcastapp/ExampleInstrumentedTest.java
@@ -1,8 +1,10 @@
-package com.example.jyheo.broadcastapp;
+package com.example.broadcastapp;
 
 import android.content.Context;
-import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
+
+
+import androidx.test.InstrumentationRegistry;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
diff --git a/BroadcastApp/app/src/main/AndroidManifest.xml b/BroadcastApp/app/src/main/AndroidManifest.xml
index 1d0b26f..9043987 100644
--- a/BroadcastApp/app/src/main/AndroidManifest.xml
+++ b/BroadcastApp/app/src/main/AndroidManifest.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.jyheo.broadcastapp">
+    package="com.example.broadcastapp">
 
     <uses-permission android:name="android.permission.RECEIVE_SMS" />
 
@@ -14,7 +14,6 @@
         <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
-
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
@@ -24,14 +23,9 @@
             android:enabled="true"
             android:exported="true">
             <intent-filter>
-                <action android:name="android.intent.action.ACTION_POWER_CONNECTED" />
+                <action android:name="android.intent.action.TIME_SET" />
             </intent-filter>
         </receiver>
-        <receiver
-            android:name=".MySMSReceiver"
-            android:enabled="true"
-            android:exported="true">
-        </receiver>
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/BroadcastApp/app/src/main/java/com/example/broadcastapp/MainActivity.java b/BroadcastApp/app/src/main/java/com/example/broadcastapp/MainActivity.java
new file mode 100644
index 0000000..97d7b15
--- /dev/null
+++ b/BroadcastApp/app/src/main/java/com/example/broadcastapp/MainActivity.java
@@ -0,0 +1,75 @@
+package com.example.broadcastapp;
+
+import android.Manifest;
+import android.content.IntentFilter;
+import android.content.pm.PackageManager;
+import android.provider.Telephony;
+import android.os.Bundle;
+
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+
+import com.example.broadcastapp.databinding.ActivityMainBinding;
+
+public class MainActivity extends AppCompatActivity {
+
+    private MySMSReceiver mReceiver;
+
+    private final int RC_SMS_RECEIVED = 1;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        final ActivityMainBinding binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+
+        mReceiver = new MySMSReceiver();
+        mReceiver.setOnSmsReceived(binding.textview::setText);
+        /*
+        mReceiver.setOnSmsReceived(m -> binding.textview.setText(m));
+
+        mReceiver.setOnSmsReceived(new MySMSReceiver.OnSmsReceived() {
+            @Override
+            public void onReceived(String msg) {
+                binding.textview.setText(msg);
+            }
+        });*/
+
+        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.RECEIVE_SMS)
+                != PackageManager.PERMISSION_GRANTED) {
+            ActivityCompat.requestPermissions(this,
+                    new String[]{Manifest.permission.RECEIVE_SMS}, RC_SMS_RECEIVED);
+        }
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        registerReceiver(mReceiver, new IntentFilter(Telephony.Sms.Intents.SMS_RECEIVED_ACTION));
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        unregisterReceiver(mReceiver);
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+
+        if (requestCode == RC_SMS_RECEIVED) {
+            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                // permission granted
+            } else {
+                new AlertDialog.Builder(this).setTitle("Permission!")
+                        .setMessage("RECEIVE_SMS permission is required to receive SMS.\nPress OK to grant the permission.")
+                        .setPositiveButton("OK", ((dialog, which) -> ActivityCompat.requestPermissions(this,
+                                new String[]{Manifest.permission.RECEIVE_SMS}, RC_SMS_RECEIVED)))
+                        .setNegativeButton("Cancel", null)
+                        .create().show();
+            }
+        }
+    }
+}
diff --git a/BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MyBroadcastReceiver.java b/BroadcastApp/app/src/main/java/com/example/broadcastapp/MyBroadcastReceiver.java
similarity index 53%
rename from BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MyBroadcastReceiver.java
rename to BroadcastApp/app/src/main/java/com/example/broadcastapp/MyBroadcastReceiver.java
index 0c1f8e9..63c9455 100644
--- a/BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MyBroadcastReceiver.java
+++ b/BroadcastApp/app/src/main/java/com/example/broadcastapp/MyBroadcastReceiver.java
@@ -1,4 +1,4 @@
-package com.example.jyheo.broadcastapp;
+package com.example.broadcastapp;
 
 import android.content.BroadcastReceiver;
 import android.content.Context;
@@ -11,11 +11,8 @@ public class MyBroadcastReceiver extends BroadcastReceiver {
 
     @Override
     public void onReceive(Context context, Intent intent) {
-        StringBuilder sb = new StringBuilder();
-        sb.append("Action: " + intent.getAction() + "\n");
-        sb.append("URI: " + intent.toUri(Intent.URI_INTENT_SCHEME).toString() + "\n");
-        String log = sb.toString();
+        String log = "Action: " + intent.getAction() + "\n" +
+                "URI: " + intent.toUri(Intent.URI_INTENT_SCHEME);
         Log.d(TAG, log);
-        Toast.makeText(context, log, Toast.LENGTH_LONG).show();
     }
 }
diff --git a/BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MySMSReceiver.java b/BroadcastApp/app/src/main/java/com/example/broadcastapp/MySMSReceiver.java
similarity index 57%
rename from BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MySMSReceiver.java
rename to BroadcastApp/app/src/main/java/com/example/broadcastapp/MySMSReceiver.java
index 250b261..9357d9d 100644
--- a/BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MySMSReceiver.java
+++ b/BroadcastApp/app/src/main/java/com/example/broadcastapp/MySMSReceiver.java
@@ -1,30 +1,40 @@
-package com.example.jyheo.broadcastapp;
+package com.example.broadcastapp;
 
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
-import android.os.Bundle;
 import android.provider.Telephony;
 import android.telephony.SmsMessage;
-import android.util.StringBuilderPrinter;
 import android.widget.Toast;
 
 public class MySMSReceiver extends BroadcastReceiver {
 
+    interface OnSmsReceived {
+        void onReceived(String msg);
+    }
+
+    private OnSmsReceived onSmsReceived = null;
+
+    public void setOnSmsReceived(OnSmsReceived smsReceived) {
+        onSmsReceived = smsReceived;
+    }
+
     @Override
     public void onReceive(Context context, Intent intent) {
-        if (intent.getAction().equals(Telephony.Sms.Intents.SMS_RECEIVED_ACTION)) {
+        if (Telephony.Sms.Intents.SMS_RECEIVED_ACTION.equals(intent.getAction())) {
             SmsMessage[] messages = Telephony.Sms.Intents.getMessagesFromIntent(intent);
             if (messages != null) {
                 if (messages.length == 0)
                     return;
                 StringBuilder sb = new StringBuilder();
-                for (int i = 0; i < messages.length; i++) {
-                    sb.append(messages[i].getMessageBody());
+                for (SmsMessage smsMessage : messages) {
+                    sb.append(smsMessage.getMessageBody());
                 }
                 String sender = messages[0].getOriginatingAddress();
                 String message = sb.toString();
-                Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
+                //Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
+                if (onSmsReceived != null)
+                    onSmsReceived.onReceived(message);
                 // prevent any other broadcast receivers from receiving broadcast
                 // abortBroadcast();
             }
diff --git a/BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MainActivity.java b/BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MainActivity.java
deleted file mode 100644
index 6b8b285..0000000
--- a/BroadcastApp/app/src/main/java/com/example/jyheo/broadcastapp/MainActivity.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package com.example.jyheo.broadcastapp;
-
-import android.Manifest;
-import android.content.BroadcastReceiver;
-import android.content.Intent;
-import android.content.IntentFilter;
-import android.content.pm.PackageManager;
-import android.net.ConnectivityManager;
-import android.provider.Telephony;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.content.ContextCompat;
-import android.support.v7.app.AppCompatActivity;
-import android.os.Bundle;
-
-public class MainActivity extends AppCompatActivity {
-
-    BroadcastReceiver br = new MyBroadcastReceiver();
-    BroadcastReceiver br_sms = new MySMSReceiver();
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
-
-        IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
-        intentFilter.addAction(Intent.ACTION_AIRPLANE_MODE_CHANGED);
-        registerReceiver(br, intentFilter);
-
-        requestPermission();
-
-        IntentFilter intentFilter2 = new IntentFilter(Telephony.Sms.Intents.SMS_RECEIVED_ACTION);
-        registerReceiver(br_sms, intentFilter2);
-    }
-
-    @Override
-    protected void onDestroy() {
-        unregisterReceiver(br);
-        unregisterReceiver(br_sms);
-        super.onDestroy();
-    }
-
-    private void requestPermission() {
-        if (ContextCompat.checkSelfPermission(this,
-                Manifest.permission.RECEIVE_SMS) != PackageManager.PERMISSION_GRANTED) {
-            ActivityCompat.requestPermissions(this,
-                    new String[]{Manifest.permission.RECEIVE_SMS}, 1);
-        } else {
-
-        }
-    }
-
-    @Override
-    public void onRequestPermissionsResult(int requestCode,
-                                           String permissions[], int[] grantResults) {
-        if (requestCode == 1) {
-            if (grantResults.length > 0
-                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
-
-            }
-        }
-    }
-}
diff --git a/BroadcastApp/app/src/main/res/layout/activity_main.xml b/BroadcastApp/app/src/main/res/layout/activity_main.xml
index d21a527..b7974b2 100644
--- a/BroadcastApp/app/src/main/res/layout/activity_main.xml
+++ b/BroadcastApp/app/src/main/res/layout/activity_main.xml
@@ -1,18 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
-<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    tools:context="com.example.jyheo.broadcastapp.MainActivity">
+    android:layout_height="match_parent" >
 
     <TextView
+        android:id="@+id/textview"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Hello World!"
+        android:gravity="center"
+        android:text="SMS"
+        android:textSize="14sp"
+        android:textStyle="bold|italic"
         app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintLeft_toLeftOf="parent"
-        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
-</android.support.constraint.ConstraintLayout>
+</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/BroadcastApp/app/src/test/java/com/example/jyheo/broadcastapp/ExampleUnitTest.java b/BroadcastApp/app/src/test/java/com/example/broadcastapp/ExampleUnitTest.java
similarity index 90%
rename from BroadcastApp/app/src/test/java/com/example/jyheo/broadcastapp/ExampleUnitTest.java
rename to BroadcastApp/app/src/test/java/com/example/broadcastapp/ExampleUnitTest.java
index bc1dc4d..f0e713b 100644
--- a/BroadcastApp/app/src/test/java/com/example/jyheo/broadcastapp/ExampleUnitTest.java
+++ b/BroadcastApp/app/src/test/java/com/example/broadcastapp/ExampleUnitTest.java
@@ -1,4 +1,4 @@
-package com.example.jyheo.broadcastapp;
+package com.example.broadcastapp;
 
 import org.junit.Test;
 
diff --git a/BroadcastApp/build.gradle b/BroadcastApp/build.gradle
index b78a0b8..3d45f00 100644
--- a/BroadcastApp/build.gradle
+++ b/BroadcastApp/build.gradle
@@ -1,11 +1,15 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+
     repositories {
+        google()
         jcenter()
+
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.1'
+        classpath 'com.android.tools.build:gradle:4.0.0'
+
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -14,7 +18,9 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
+
     }
 }
 
diff --git a/BroadcastApp/gradle.properties b/BroadcastApp/gradle.properties
index aac7c9b..c73d239 100644
--- a/BroadcastApp/gradle.properties
+++ b/BroadcastApp/gradle.properties
@@ -1,17 +1,19 @@
 # Project-wide Gradle settings.
-
 # IDE (e.g. Android Studio) users:
 # Gradle settings configured through the IDE *will override*
 # any settings specified in this file.
-
 # For more details on how to configure your build environment visit
 # http://www.gradle.org/docs/current/userguide/build_environment.html
-
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
 org.gradle.jvmargs=-Xmx1536m
-
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
diff --git a/BroadcastApp/gradle/wrapper/gradle-wrapper.properties b/BroadcastApp/gradle/wrapper/gradle-wrapper.properties
index e46404e..dcb30cb 100644
--- a/BroadcastApp/gradle/wrapper/gradle-wrapper.properties
+++ b/BroadcastApp/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Apr 24 11:44:27 KST 2017
+#Fri Jun 05 00:00:16 KST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
diff --git a/ContentResolverEx/.idea/compiler.xml b/ContentResolverEx/.idea/compiler.xml
deleted file mode 100644
index 96cc43e..0000000
--- a/ContentResolverEx/.idea/compiler.xml
+++ /dev/null
@@ -1,22 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <resourceExtensions />
-    <wildcardResourcePatterns>
-      <entry name="!?*.java" />
-      <entry name="!?*.form" />
-      <entry name="!?*.class" />
-      <entry name="!?*.groovy" />
-      <entry name="!?*.scala" />
-      <entry name="!?*.flex" />
-      <entry name="!?*.kt" />
-      <entry name="!?*.clj" />
-      <entry name="!?*.aj" />
-    </wildcardResourcePatterns>
-    <annotationProcessing>
-      <profile default="true" name="Default" enabled="false">
-        <processorPath useClasspath="true" />
-      </profile>
-    </annotationProcessing>
-  </component>
-</project>
\ No newline at end of file
diff --git a/ContentResolverEx/.idea/copyright/profiles_settings.xml b/ContentResolverEx/.idea/copyright/profiles_settings.xml
deleted file mode 100644
index e7bedf3..0000000
--- a/ContentResolverEx/.idea/copyright/profiles_settings.xml
+++ /dev/null
@@ -1,3 +0,0 @@
-<component name="CopyrightManager">
-  <settings default="" />
-</component>
\ No newline at end of file
diff --git a/ContentResolverEx/.idea/encodings.xml b/ContentResolverEx/.idea/encodings.xml
deleted file mode 100644
index 97626ba..0000000
--- a/ContentResolverEx/.idea/encodings.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="Encoding">
-    <file url="PROJECT" charset="UTF-8" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/ContentResolverEx/.idea/gradle.xml b/ContentResolverEx/.idea/gradle.xml
index 0e23f8e..ac6b0ae 100644
--- a/ContentResolverEx/.idea/gradle.xml
+++ b/ContentResolverEx/.idea/gradle.xml
@@ -1,11 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
-        <option name="distributionType" value="LOCAL" />
+        <option name="testRunner" value="PLATFORM" />
+        <option name="distributionType" value="DEFAULT_WRAPPED" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
-        <option name="gradleHome" value="$APPLICATION_HOME_DIR$/gradle/gradle-2.14.1" />
+        <option name="gradleJvm" value="1.8" />
         <option name="modules">
           <set>
             <option value="$PROJECT_DIR$" />
diff --git a/ContentResolverEx/.idea/misc.xml b/ContentResolverEx/.idea/misc.xml
index 9adc8c9..703e5d4 100644
--- a/ContentResolverEx/.idea/misc.xml
+++ b/ContentResolverEx/.idea/misc.xml
@@ -1,62 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
+  <component name="CMakeSettings">
+    <configurations>
+      <configuration PROFILE_NAME="Debug" CONFIG_NAME="Debug" />
+    </configurations>
   </component>
-  <component name="NullableNotNullManager">
-    <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
-    <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
-    <option name="myNullables">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
-        </list>
-      </value>
-    </option>
-    <option name="myNotNulls">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
-        </list>
-      </value>
-    </option>
-  </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
     <option name="id" value="Android" />
   </component>
-  <component name="masterDetails">
-    <states>
-      <state key="ProjectJDKs.UI">
-        <settings>
-          <last-edited>Android API 24 Platform</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-    </states>
-  </component>
 </project>
\ No newline at end of file
diff --git a/ContentResolverEx/.idea/modules.xml b/ContentResolverEx/.idea/modules.xml
index 1f6249e..0b99086 100644
--- a/ContentResolverEx/.idea/modules.xml
+++ b/ContentResolverEx/.idea/modules.xml
@@ -2,8 +2,8 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/ContentResolverEx.iml" filepath="$PROJECT_DIR$/ContentResolverEx.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/ContentResolverEx.iml" filepath="$PROJECT_DIR$/.idea/modules/ContentResolverEx.iml" group="ContentResolverEx" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/app/app.iml" filepath="$PROJECT_DIR$/.idea/modules/app/app.iml" group="ContentResolverEx/app" />
     </modules>
   </component>
 </project>
\ No newline at end of file
diff --git a/ContentResolverEx/app/build.gradle b/ContentResolverEx/app/build.gradle
index 8a15d9d..fe831f3 100644
--- a/ContentResolverEx/app/build.gradle
+++ b/ContentResolverEx/app/build.gradle
@@ -1,29 +1,41 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.0"
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
+
     defaultConfig {
-        applicationId "com.example.jyheo.contentresolverex"
-        minSdkVersion 22
-        targetSdkVersion 25
+        applicationId "com.example.contentresolverex"
+        minSdkVersion 23
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
+
     buildTypes {
         release {
             minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
+
+    buildFeatures {
+        viewBinding true
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    })
-    compile 'com.android.support:appcompat-v7:25.2.0'
-    testCompile 'junit:junit:4.12'
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
 }
diff --git a/ContentResolverEx/app/src/main/java/com/example/jyheo/contentresolverex/MainActivity.java b/ContentResolverEx/app/src/main/java/com/example/jyheo/contentresolverex/MainActivity.java
index 1942c80..3b9ca1b 100644
--- a/ContentResolverEx/app/src/main/java/com/example/jyheo/contentresolverex/MainActivity.java
+++ b/ContentResolverEx/app/src/main/java/com/example/jyheo/contentresolverex/MainActivity.java
@@ -4,50 +4,71 @@
 import android.content.pm.PackageManager;
 import android.database.Cursor;
 import android.provider.CallLog;
-import android.support.annotation.NonNull;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.content.ContextCompat;
-import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
-import android.widget.ArrayAdapter;
-import android.widget.ListView;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+import androidx.cursoradapter.widget.SimpleCursorAdapter;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
 
-import java.util.ArrayList;
+import com.example.jyheo.contentresolverex.databinding.ActivityMainBinding;
 
 public class MainActivity extends AppCompatActivity {
 
     final int REQUEST_CODE_PERM_READ_CALL_LOG = 1;
+    ActivityMainBinding binding;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
-
-        if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CALL_LOG) == PackageManager.PERMISSION_GRANTED) {
-            updateCallLog();
-        } else {
-            ActivityCompat.requestPermissions(this,
-                    new String[]{Manifest.permission.READ_CALL_LOG}, REQUEST_CODE_PERM_READ_CALL_LOG);
-        }
+        binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
 
+        binding.button.setOnClickListener(v -> updateCallLog());
     }
 
     private void updateCallLog() {
-        if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CALL_LOG) != PackageManager.PERMISSION_GRANTED)
+        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_CALL_LOG)
+                != PackageManager.PERMISSION_GRANTED) {
+            ActivityCompat.requestPermissions(this,
+                    new String[]{Manifest.permission.READ_CALL_LOG}, REQUEST_CODE_PERM_READ_CALL_LOG);
             return;
-        Cursor cursor = getContentResolver().query(CallLog.Calls.CONTENT_URI, new String[]{CallLog.Calls.NUMBER}, null, null, null);
-        int number_index = cursor.getColumnIndex(CallLog.Calls.NUMBER);
-        ArrayList<String> call_list = new ArrayList<>();
-        while (cursor.moveToNext()) {
-            String num = cursor.getString(number_index);
-            call_list.add(num);
         }
-        cursor.close();
 
-        ListView lv = (ListView)findViewById(R.id.calllog);
-        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,
-                call_list);
-        lv.setAdapter(adapter);
+        Cursor cursor = getContentResolver().query(CallLog.Calls.CONTENT_URI,
+                new String[]{CallLog.Calls._ID, CallLog.Calls.NUMBER},  // _ID is required for cursoradapter
+                null, null, null);
+        binding.calllog.setAdapter(new SimpleCursorAdapter(this,
+                android.R.layout.simple_list_item_1, cursor,
+                new String[]{CallLog.Calls.NUMBER}, new int[]{android.R.id.text1}, 0));
+
+        /* // by CursorLoader
+         LoaderManager.getInstance(this).initLoader(0, null, new LoaderManager.LoaderCallbacks<Cursor>() {
+            @NonNull
+            @Override
+            public Loader<Cursor> onCreateLoader(int id, @Nullable Bundle args) {
+                return new CursorLoader(MainActivity.this, CallLog.Calls.CONTENT_URI,
+                        new String[]{CallLog.Calls._ID, CallLog.Calls.NUMBER},
+                        null, null, null);
+            }
+
+            @Override
+            public void onLoadFinished(@NonNull Loader<Cursor> loader, Cursor data) {
+                binding.calllog.setAdapter(new SimpleCursorAdapter(MainActivity.this,
+                        android.R.layout.simple_list_item_1, data,
+                        new String[]{CallLog.Calls.NUMBER}, new int[]{android.R.id.text1}, 0));
+            }
+
+            @Override
+            public void onLoaderReset(@NonNull Loader<Cursor> loader) {
+                binding.calllog.setAdapter(null);
+            }
+        });*/
+
     }
 
     @Override
@@ -58,6 +79,12 @@ public void onRequestPermissionsResult(int requestCode, @NonNull String[] permis
                 updateCallLog();
             } else {
                 // permission for READ_CALL_LOG rejected!
+                new AlertDialog.Builder(this).setTitle("Permission!")
+                        .setMessage("READ_CALL_LOG permission is required to list the call log.\nPress OK to grant the permission.")
+                        .setPositiveButton("OK", ((dialog, which) -> ActivityCompat.requestPermissions(this,
+                                new String[]{Manifest.permission.READ_CALL_LOG}, REQUEST_CODE_PERM_READ_CALL_LOG)))
+                        .setNegativeButton("Cancel", null)
+                        .create().show();
             }
         }
     }
diff --git a/ContentResolverEx/app/src/main/res/layout/activity_main.xml b/ContentResolverEx/app/src/main/res/layout/activity_main.xml
index faf0540..be26cb3 100644
--- a/ContentResolverEx/app/src/main/res/layout/activity_main.xml
+++ b/ContentResolverEx/app/src/main/res/layout/activity_main.xml
@@ -1,22 +1,38 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/activity_main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:paddingBottom="@dimen/activity_vertical_margin"
-    android:paddingLeft="@dimen/activity_horizontal_margin"
-    android:paddingRight="@dimen/activity_horizontal_margin"
-    android:paddingTop="@dimen/activity_vertical_margin"
-    android:orientation="vertical"
+    android:padding="5dp"
     tools:context="com.example.jyheo.contentresolverex.MainActivity">
 
+
     <TextView
+        android:id="@+id/textView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Call log:" />
+        android:text="Call log:"
+        android:textSize="14sp"
+        app:layout_constraintBaseline_toBaselineOf="@+id/button"
+        app:layout_constraintEnd_toStartOf="@+id/button"
+        app:layout_constraintStart_toStartOf="parent" />
+
+    <Button
+        android:id="@+id/button"
+        android:layout_width="wrap_content"
+        android:layout_height="48dp"
+        android:text="Refresh"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+
     <ListView
         android:id="@+id/calllog"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"/>
-</LinearLayout>
+        android:layout_width="wrap_content"
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/button" />
+</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/ContentResolverEx/build.gradle b/ContentResolverEx/build.gradle
index 74b2ab0..3d45f00 100644
--- a/ContentResolverEx/build.gradle
+++ b/ContentResolverEx/build.gradle
@@ -1,11 +1,15 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+
     repositories {
+        google()
         jcenter()
+
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.3'
+        classpath 'com.android.tools.build:gradle:4.0.0'
+
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -14,7 +18,9 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
+
     }
 }
 
diff --git a/ContentResolverEx/gradle.properties b/ContentResolverEx/gradle.properties
index aac7c9b..c73d239 100644
--- a/ContentResolverEx/gradle.properties
+++ b/ContentResolverEx/gradle.properties
@@ -1,17 +1,19 @@
 # Project-wide Gradle settings.
-
 # IDE (e.g. Android Studio) users:
 # Gradle settings configured through the IDE *will override*
 # any settings specified in this file.
-
 # For more details on how to configure your build environment visit
 # http://www.gradle.org/docs/current/userguide/build_environment.html
-
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
 org.gradle.jvmargs=-Xmx1536m
-
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
diff --git a/ContentResolverEx/gradle/wrapper/gradle-wrapper.properties b/ContentResolverEx/gradle/wrapper/gradle-wrapper.properties
index 04e285f..dcb30cb 100644
--- a/ContentResolverEx/gradle/wrapper/gradle-wrapper.properties
+++ b/ContentResolverEx/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Dec 28 10:00:20 PST 2015
+#Fri Jun 05 00:00:16 KST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
diff --git a/FileExample/.gitignore b/FileExample/.gitignore
new file mode 100644
index 0000000..603b140
--- /dev/null
+++ b/FileExample/.gitignore
@@ -0,0 +1,14 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
diff --git a/FileExample/app/.gitignore b/FileExample/app/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/FileExample/app/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/FileExample/app/build.gradle b/FileExample/app/build.gradle
new file mode 100644
index 0000000..f0f347e
--- /dev/null
+++ b/FileExample/app/build.gradle
@@ -0,0 +1,41 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 30
+
+    defaultConfig {
+        applicationId "com.example.fileexample"
+        minSdkVersion 23
+        targetSdkVersion 30
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+
+    buildFeatures {
+        viewBinding true
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+    buildToolsVersion '30.0.0'
+}
+
+dependencies {
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+
+}
\ No newline at end of file
diff --git a/FileExample/app/proguard-rules.pro b/FileExample/app/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/FileExample/app/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/FileExample/app/src/androidTest/java/com/example/fileexample/ExampleInstrumentedTest.java b/FileExample/app/src/androidTest/java/com/example/fileexample/ExampleInstrumentedTest.java
new file mode 100644
index 0000000..d4cb7e0
--- /dev/null
+++ b/FileExample/app/src/androidTest/java/com/example/fileexample/ExampleInstrumentedTest.java
@@ -0,0 +1,26 @@
+package com.example.fileexample;
+
+import android.content.Context;
+
+import androidx.test.platform.app.InstrumentationRegistry;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        assertEquals("com.example.fileexample", appContext.getPackageName());
+    }
+}
\ No newline at end of file
diff --git a/FileExample/app/src/main/AndroidManifest.xml b/FileExample/app/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..b441a30
--- /dev/null
+++ b/FileExample/app/src/main/AndroidManifest.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.fileexample">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <activity android:name=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file
diff --git a/FileExample/app/src/main/java/com/example/fileexample/MainActivity.java b/FileExample/app/src/main/java/com/example/fileexample/MainActivity.java
new file mode 100644
index 0000000..d367956
--- /dev/null
+++ b/FileExample/app/src/main/java/com/example/fileexample/MainActivity.java
@@ -0,0 +1,68 @@
+package com.example.fileexample;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import android.os.Bundle;
+import android.os.Environment;
+import android.widget.Toast;
+
+import com.example.fileexample.databinding.ActivityMainBinding;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+
+public class MainActivity extends AppCompatActivity {
+
+    private ActivityMainBinding binding;
+    private final String filename = "appfile.txt";
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+
+        binding.btnReadIn.setOnClickListener(v -> readData(new File(getFilesDir(), filename)));
+        binding.btnWriteIn.setOnClickListener(v -> writeData(new File(getFilesDir(), filename)));
+
+        if (isExternalStorageMounted()) {
+            binding.btnReadExt.setOnClickListener(v -> readData(new File(getExternalFilesDir(null), filename)));
+            binding.btnWriteExt.setOnClickListener(v -> writeData(new File(getExternalFilesDir(null), filename)));
+        } else {
+            binding.btnReadExt.setOnClickListener(v ->
+                    Toast.makeText(this, "External Stroage is not mounted.", Toast.LENGTH_LONG).show());
+            binding.btnWriteExt.setOnClickListener(v ->
+                    Toast.makeText(this, "External Stroage is not mounted.", Toast.LENGTH_LONG).show());
+        }
+    }
+
+    void readData(File file) {
+        try {
+            FileInputStream fis = new FileInputStream(file);
+            byte[] data = new byte[fis.available()];
+            fis.read(data);
+            binding.editText.setText(new String(data));
+            fis.close();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+    }
+
+    void writeData(File file) {
+        try {
+            FileOutputStream fos = new FileOutputStream(file);
+            fos.write(binding.editText.getText().toString().getBytes());
+            fos.close();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    public boolean isExternalStorageMounted() {
+        String state = Environment.getExternalStorageState();
+        return Environment.MEDIA_MOUNTED.equals(state);
+    }
+}
\ No newline at end of file
diff --git a/FileExample/app/src/main/res/drawable-v24/ic_launcher_foreground.xml b/FileExample/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
new file mode 100644
index 0000000..2b068d1
--- /dev/null
+++ b/FileExample/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path android:pathData="M31,63.928c0,0 6.4,-11 12.1,-13.1c7.2,-2.6 26,-1.4 26,-1.4l38.1,38.1L107,108.928l-32,-1L31,63.928z">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="85.84757"
+                android:endY="92.4963"
+                android:startX="42.9492"
+                android:startY="49.59793"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M65.3,45.828l3.8,-6.6c0.2,-0.4 0.1,-0.9 -0.3,-1.1c-0.4,-0.2 -0.9,-0.1 -1.1,0.3l-3.9,6.7c-6.3,-2.8 -13.4,-2.8 -19.7,0l-3.9,-6.7c-0.2,-0.4 -0.7,-0.5 -1.1,-0.3C38.8,38.328 38.7,38.828 38.9,39.228l3.8,6.6C36.2,49.428 31.7,56.028 31,63.928h46C76.3,56.028 71.8,49.428 65.3,45.828zM43.4,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2c-0.3,-0.7 -0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C45.3,56.528 44.5,57.328 43.4,57.328L43.4,57.328zM64.6,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2s-0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C66.5,56.528 65.6,57.328 64.6,57.328L64.6,57.328z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>
\ No newline at end of file
diff --git a/FileExample/app/src/main/res/drawable/ic_launcher_background.xml b/FileExample/app/src/main/res/drawable/ic_launcher_background.xml
new file mode 100644
index 0000000..07d5da9
--- /dev/null
+++ b/FileExample/app/src/main/res/drawable/ic_launcher_background.xml
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#3DDC84"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+</vector>
diff --git a/FileExample/app/src/main/res/layout/activity_main.xml b/FileExample/app/src/main/res/layout/activity_main.xml
new file mode 100644
index 0000000..2d9cb27
--- /dev/null
+++ b/FileExample/app/src/main/res/layout/activity_main.xml
@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".MainActivity">
+
+    <Button
+        android:id="@+id/btnReadIn"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Read Internal"
+        app:layout_constraintBottom_toTopOf="@+id/btnWriteIn"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_chainStyle="packed" />
+
+    <Button
+        android:id="@+id/btnWriteIn"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Write Internal"
+        app:layout_constraintBottom_toTopOf="@+id/btnReadExt"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/btnReadIn" />
+
+    <Button
+        android:id="@+id/btnReadExt"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Read External"
+        app:layout_constraintBottom_toTopOf="@+id/btnWriteExt"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/btnWriteIn" />
+
+    <Button
+        android:id="@+id/btnWriteExt"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Write External"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/btnReadExt" />
+
+    <EditText
+        android:id="@+id/editText"
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        android:layout_marginStart="8dp"
+        android:ems="10"
+        android:inputType="textPersonName"
+        android:text="Name"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toEndOf="@+id/btnWriteExt"
+        app:layout_constraintTop_toTopOf="parent" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/FileExample/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml b/FileExample/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/FileExample/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/FileExample/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml b/FileExample/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/FileExample/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/FileExample/app/src/main/res/mipmap-hdpi/ic_launcher.png b/FileExample/app/src/main/res/mipmap-hdpi/ic_launcher.png
new file mode 100644
index 0000000..a571e60
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-hdpi/ic_launcher.png differ
diff --git a/FileExample/app/src/main/res/mipmap-hdpi/ic_launcher_round.png b/FileExample/app/src/main/res/mipmap-hdpi/ic_launcher_round.png
new file mode 100644
index 0000000..61da551
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-hdpi/ic_launcher_round.png differ
diff --git a/FileExample/app/src/main/res/mipmap-mdpi/ic_launcher.png b/FileExample/app/src/main/res/mipmap-mdpi/ic_launcher.png
new file mode 100644
index 0000000..c41dd28
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-mdpi/ic_launcher.png differ
diff --git a/FileExample/app/src/main/res/mipmap-mdpi/ic_launcher_round.png b/FileExample/app/src/main/res/mipmap-mdpi/ic_launcher_round.png
new file mode 100644
index 0000000..db5080a
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-mdpi/ic_launcher_round.png differ
diff --git a/FileExample/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/FileExample/app/src/main/res/mipmap-xhdpi/ic_launcher.png
new file mode 100644
index 0000000..6dba46d
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-xhdpi/ic_launcher.png differ
diff --git a/FileExample/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png b/FileExample/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..da31a87
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png differ
diff --git a/FileExample/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/FileExample/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
new file mode 100644
index 0000000..15ac681
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-xxhdpi/ic_launcher.png differ
diff --git a/FileExample/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png b/FileExample/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..b216f2d
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png differ
diff --git a/FileExample/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/FileExample/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
new file mode 100644
index 0000000..f25a419
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ
diff --git a/FileExample/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png b/FileExample/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..e96783c
Binary files /dev/null and b/FileExample/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png differ
diff --git a/FileExample/app/src/main/res/values/colors.xml b/FileExample/app/src/main/res/values/colors.xml
new file mode 100644
index 0000000..4faecfa
--- /dev/null
+++ b/FileExample/app/src/main/res/values/colors.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="colorPrimary">#6200EE</color>
+    <color name="colorPrimaryDark">#3700B3</color>
+    <color name="colorAccent">#03DAC5</color>
+</resources>
\ No newline at end of file
diff --git a/FileExample/app/src/main/res/values/strings.xml b/FileExample/app/src/main/res/values/strings.xml
new file mode 100644
index 0000000..de2550d
--- /dev/null
+++ b/FileExample/app/src/main/res/values/strings.xml
@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">FileExample</string>
+</resources>
\ No newline at end of file
diff --git a/FileExample/app/src/main/res/values/styles.xml b/FileExample/app/src/main/res/values/styles.xml
new file mode 100644
index 0000000..fac9291
--- /dev/null
+++ b/FileExample/app/src/main/res/values/styles.xml
@@ -0,0 +1,10 @@
+<resources>
+    <!-- Base application theme. -->
+    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+        <!-- Customize your theme here. -->
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+    </style>
+
+</resources>
\ No newline at end of file
diff --git a/FileExample/app/src/test/java/com/example/fileexample/ExampleUnitTest.java b/FileExample/app/src/test/java/com/example/fileexample/ExampleUnitTest.java
new file mode 100644
index 0000000..7f11a75
--- /dev/null
+++ b/FileExample/app/src/test/java/com/example/fileexample/ExampleUnitTest.java
@@ -0,0 +1,17 @@
+package com.example.fileexample;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+public class ExampleUnitTest {
+    @Test
+    public void addition_isCorrect() {
+        assertEquals(4, 2 + 2);
+    }
+}
\ No newline at end of file
diff --git a/MaterialTest/build.gradle b/FileExample/build.gradle
similarity index 82%
rename from MaterialTest/build.gradle
rename to FileExample/build.gradle
index c2eea8e..da807a2 100644
--- a/MaterialTest/build.gradle
+++ b/FileExample/build.gradle
@@ -1,11 +1,11 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
-
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath "com.android.tools.build:gradle:4.0.0"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -14,10 +14,11 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
     }
 }
 
 task clean(type: Delete) {
     delete rootProject.buildDir
-}
+}
\ No newline at end of file
diff --git a/FileExample/gradle.properties b/FileExample/gradle.properties
new file mode 100644
index 0000000..c52ac9b
--- /dev/null
+++ b/FileExample/gradle.properties
@@ -0,0 +1,19 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx2048m
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app"s APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
\ No newline at end of file
diff --git a/FileExample/gradle/wrapper/gradle-wrapper.jar b/FileExample/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..f6b961f
Binary files /dev/null and b/FileExample/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/LocationAware/gradle/wrapper/gradle-wrapper.properties b/FileExample/gradle/wrapper/gradle-wrapper.properties
similarity index 78%
rename from LocationAware/gradle/wrapper/gradle-wrapper.properties
rename to FileExample/gradle/wrapper/gradle-wrapper.properties
index 364d2a2..5de1009 100644
--- a/LocationAware/gradle/wrapper/gradle-wrapper.properties
+++ b/FileExample/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Thu Aug 24 13:45:55 KST 2017
-distributionBase=GRADLE_USER_HOME
-distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+#Fri Jun 12 00:58:26 KST 2020
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
diff --git a/FileExample/gradlew b/FileExample/gradlew
new file mode 100644
index 0000000..cccdd3d
--- /dev/null
+++ b/FileExample/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/FileExample/gradlew.bat b/FileExample/gradlew.bat
new file mode 100644
index 0000000..f955316
--- /dev/null
+++ b/FileExample/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/FileExample/settings.gradle b/FileExample/settings.gradle
new file mode 100644
index 0000000..70e3262
--- /dev/null
+++ b/FileExample/settings.gradle
@@ -0,0 +1,2 @@
+include ':app'
+rootProject.name = "FileExample"
\ No newline at end of file
diff --git a/FirebaseTest/app/build.gradle b/FirebaseTest/app/build.gradle
index 5298aad..112d020 100644
--- a/FirebaseTest/app/build.gradle
+++ b/FirebaseTest/app/build.gradle
@@ -1,13 +1,14 @@
 apply plugin: 'com.android.application'
+apply plugin: 'com.google.gms.google-services'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.3"
+    compileSdkVersion 30
+    buildToolsVersion "30.0.0"
 
     defaultConfig {
         applicationId "com.example.jyheo.firebasetest"
-        minSdkVersion 22
-        targetSdkVersion 25
+        minSdkVersion 23
+        targetSdkVersion 30
         versionCode 1
         versionName "1.0"
     }
@@ -17,23 +18,22 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    buildFeatures {
+        viewBinding true
+    }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    compile 'com.android.support:appcompat-v7:25.3.1'
-    compile 'com.android.support:design:25.3.1'
-    compile 'com.google.firebase:firebase-auth:9.6.1'
-    compile 'com.google.firebase:firebase-storage:9.6.1'
-    compile 'com.google.firebase:firebase-config:9.6.1'
-    compile 'com.google.firebase:firebase-messaging:9.6.1'
-    testCompile 'junit:junit:4.12'
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    implementation 'com.google.firebase:firebase-auth:19.3.1'
+    implementation 'com.google.firebase:firebase-storage:19.1.1'
+    implementation 'com.google.firebase:firebase-database:19.3.1'
+    implementation 'com.google.firebase:firebase-config:19.1.4'
+    implementation 'com.google.firebase:firebase-messaging:20.2.1'
+    implementation 'com.google.firebase:firebase-analytics:17.4.3'
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
 }
-
-
-
-
-
-
-
-apply plugin: 'com.google.gms.google-services'
\ No newline at end of file
diff --git a/FirebaseTest/app/google-services.json b/FirebaseTest/app/google-services.json
index 9bc81fc..baec476 100644
--- a/FirebaseTest/app/google-services.json
+++ b/FirebaseTest/app/google-services.json
@@ -1,35 +1,66 @@
 {
   "project_info": {
-    "project_number": "825238159969",
-    "firebase_url": "https://fir-test-30d1c.firebaseio.com",
-    "project_id": "fir-test-30d1c",
-    "storage_bucket": "fir-test-30d1c.appspot.com"
+    "project_number": "1071702779205",
+    "firebase_url": "https://myfirebase-332e8.firebaseio.com",
+    "project_id": "myfirebase-332e8",
+    "storage_bucket": "myfirebase-332e8.appspot.com"
   },
   "client": [
     {
       "client_info": {
-        "mobilesdk_app_id": "1:825238159969:android:463092ea548218e7",
+        "mobilesdk_app_id": "1:1071702779205:android:1bcf6f7ce6e31abc",
+        "android_client_info": {
+          "package_name": "com.example.jyheo.pushnotifcm"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "1071702779205-42q75uj3tigqbpdk9ighvc7mj7o7vn0c.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCj_vN0yCA0yF96eTJZEeqxyEdklsqeObs"
+        }
+      ],
+      "services": {
+        "analytics_service": {
+          "status": 1
+        },
+        "appinvite_service": {
+          "status": 1,
+          "other_platform_oauth_client": []
+        },
+        "ads_service": {
+          "status": 2
+        }
+      }
+    },
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:1071702779205:android:463092ea548218e7",
         "android_client_info": {
           "package_name": "com.example.jyheo.firebasetest"
         }
       },
       "oauth_client": [
         {
-          "client_id": "825238159969-ggtdg93ig434fhodcmo9o7vk4qfv4sar.apps.googleusercontent.com",
+          "client_id": "1071702779205-u37f78fj2gu4elqtr414u4rjrrcq25pp.apps.googleusercontent.com",
           "client_type": 1,
           "android_info": {
             "package_name": "com.example.jyheo.firebasetest",
-            "certificate_hash": "7DE57CAA54CC70DA2D38BC6D451BFBE6FDEFD0A9"
+            "certificate_hash": "e7bfc9d45bb55566f80984888801be2f4afa650f"
           }
         },
         {
-          "client_id": "825238159969-c5vmsqg5osshsqm1tmbnqavu5cbf9m9v.apps.googleusercontent.com",
+          "client_id": "1071702779205-42q75uj3tigqbpdk9ighvc7mj7o7vn0c.apps.googleusercontent.com",
           "client_type": 3
         }
       ],
       "api_key": [
         {
-          "current_key": "AIzaSyB0bh7z69uMcQtJf5Q53Zrjy8QDB94UMXU"
+          "current_key": "AIzaSyCj_vN0yCA0yF96eTJZEeqxyEdklsqeObs"
         }
       ],
       "services": {
@@ -37,13 +68,8 @@
           "status": 1
         },
         "appinvite_service": {
-          "status": 2,
-          "other_platform_oauth_client": [
-            {
-              "client_id": "825238159969-c5vmsqg5osshsqm1tmbnqavu5cbf9m9v.apps.googleusercontent.com",
-              "client_type": 3
-            }
-          ]
+          "status": 1,
+          "other_platform_oauth_client": []
         },
         "ads_service": {
           "status": 2
diff --git a/FirebaseTest/app/src/main/AndroidManifest.xml b/FirebaseTest/app/src/main/AndroidManifest.xml
index b378c32..8003eb8 100644
--- a/FirebaseTest/app/src/main/AndroidManifest.xml
+++ b/FirebaseTest/app/src/main/AndroidManifest.xml
@@ -15,19 +15,14 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".MainActivity"></activity>
-        <service android:name=".MyFirebaseMessagingService">
-            <intent-filter>
-                <action android:name="com.google.firebase.MESSAGING_EVENT"/>
-            </intent-filter>
-        </service>
-        <service android:name=".MyFirebaseInstanceIDService">
+        <activity android:name=".MainActivity"/>
+        <service android:name=".MyFirebaseMessagingService"
+            android:exported="false">
             <intent-filter>
-                <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
+                <action android:name="com.google.firebase.MESSAGING_EVENT"/>
             </intent-filter>
         </service>
 
-
 </application>
 
 </manifest>
\ No newline at end of file
diff --git a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/LoginActivity.java b/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/LoginActivity.java
index 4ad5ed2..ddbe73b 100644
--- a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/LoginActivity.java
+++ b/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/LoginActivity.java
@@ -1,98 +1,54 @@
 package com.example.jyheo.firebasetest;
 
 import android.content.Intent;
-import android.support.annotation.NonNull;
-import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.widget.EditText;
 import android.widget.Toast;
+import androidx.appcompat.app.AppCompatActivity;
 
+import com.example.jyheo.firebasetest.databinding.ActivityLoginBinding;
 import com.google.android.gms.tasks.OnCompleteListener;
 import com.google.android.gms.tasks.Task;
 import com.google.firebase.auth.AuthResult;
 import com.google.firebase.auth.FirebaseAuth;
 import com.google.firebase.auth.FirebaseUser;
 import com.google.firebase.iid.FirebaseInstanceId;
+import androidx.annotation.NonNull;
 
 public class LoginActivity extends AppCompatActivity {
 
     private final static String TAG = "LoginActivity";
     private FirebaseAuth mAuth;
-    private FirebaseAuth.AuthStateListener mAuthListener;
+    private ActivityLoginBinding binding;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_login);
-
-        if (getIntent().getExtras() != null) {
-            for (String key : getIntent().getExtras().keySet()) {
-                Object value = getIntent().getExtras().get(key);
-                Log.d(TAG, "Key: " + key + " Value: " + value);
-            }
-        }
-
-        String token = FirebaseInstanceId.getInstance().getToken();
-        Log.d(TAG, "InstanceID token: " + token);
+        binding = ActivityLoginBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
 
         mAuth = FirebaseAuth.getInstance();
-
-        mAuthListener = new FirebaseAuth.AuthStateListener() {
-            @Override
-            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
-                FirebaseUser user = firebaseAuth.getCurrentUser();
-                if (user != null) {
-                    // User is signed in
-                    Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid());
-
-                    Intent it = new Intent(LoginActivity.this, MainActivity.class);
-                    startActivity(it);
-                } else {
-                    // User is signed out
-                    Log.d(TAG, "onAuthStateChanged:signed_out");
-                }
-                // ...
-            }
-        };
     }
 
     public void onButtonLogin(View v) {
-        String email = ((EditText)findViewById(R.id.etEmail)).getText().toString();
-        String password = ((EditText)findViewById(R.id.etPassword)).getText().toString();
+        String email = binding.etEmail.getText().toString();
+        String password = binding.etPassword.getText().toString();
         mAuth.signInWithEmailAndPassword(email, password)
                 .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                     @Override
                     public void onComplete(@NonNull Task<AuthResult> task) {
                         Log.d(TAG, "signInWithEmail:onComplete:" + task.isSuccessful());
-
-                        // If sign in fails, display a message to the user. If sign in succeeds
-                        // the auth state listener will be notified and logic to handle the
-                        // signed in user can be handled in the listener.
-                        if (!task.isSuccessful()) {
+                        if (task.isSuccessful()) {
+                            Intent it = new Intent(LoginActivity.this, MainActivity.class);
+                            startActivity(it);
+                        } else {
                             Log.w(TAG, "signInWithEmail", task.getException());
                             Toast.makeText(LoginActivity.this, "Authentication failed.",
                                     Toast.LENGTH_SHORT).show();
                         }
-
-                        // ...
                     }
                 });
     }
-
-    @Override
-    public void onStart() {
-        super.onStart();
-        mAuth.addAuthStateListener(mAuthListener);
-    }
-
-    @Override
-    public void onStop() {
-        super.onStop();
-        if (mAuthListener != null) {
-            mAuth.removeAuthStateListener(mAuthListener);
-        }
-    }
-
 }
diff --git a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MainActivity.java b/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MainActivity.java
index 9d82063..440e87a 100644
--- a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MainActivity.java
+++ b/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MainActivity.java
@@ -2,20 +2,29 @@
 
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
-import android.support.annotation.NonNull;
-import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.widget.ImageView;
-import android.widget.TextView;
+import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AppCompatActivity;
+
+import com.example.jyheo.firebasetest.databinding.ActivityMainBinding;
 import com.google.android.gms.tasks.OnCompleteListener;
 import com.google.android.gms.tasks.OnFailureListener;
 import com.google.android.gms.tasks.OnSuccessListener;
 import com.google.android.gms.tasks.Task;
 import com.google.firebase.auth.FirebaseAuth;
 import com.google.firebase.auth.FirebaseUser;
+import com.google.firebase.database.DataSnapshot;
+import com.google.firebase.database.DatabaseError;
+import com.google.firebase.database.DatabaseReference;
+import com.google.firebase.database.FirebaseDatabase;
+import com.google.firebase.database.ValueEventListener;
+import com.google.firebase.iid.FirebaseInstanceId;
+import com.google.firebase.iid.InstanceIdResult;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfig;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigSettings;
 import com.google.firebase.storage.FirebaseStorage;
@@ -27,11 +36,13 @@ public class MainActivity extends AppCompatActivity {
     private FirebaseAuth mAuth;
     private FirebaseStorage mFirebaseStorage;
     private FirebaseRemoteConfig mFirebaseRemoteConfig;
+    private ActivityMainBinding binding;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
+        binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
 
         mAuth = FirebaseAuth.getInstance();
         FirebaseUser user = mAuth.getCurrentUser();
@@ -43,25 +54,23 @@ protected void onCreate(Bundle savedInstanceState) {
 
         mFirebaseStorage = FirebaseStorage.getInstance();
         mFirebaseRemoteConfig = FirebaseRemoteConfig.getInstance();
-
-        // Create Remote Config Setting to enable developer mode.
-        // Fetching configs from the server is normally limited to 5 requests per hour.
-        // Enabling developer mode allows many more requests to be made per hour, so developers
-        // can test different config values during development.
         FirebaseRemoteConfigSettings configSettings = new FirebaseRemoteConfigSettings.Builder()
-                .setDeveloperModeEnabled(BuildConfig.DEBUG)
+                .setMinimumFetchIntervalInSeconds(3600) // For development only not for production!, default is 12 hours
                 .build();
-        mFirebaseRemoteConfig.setConfigSettings(configSettings);
-
-        mFirebaseRemoteConfig.setDefaults(R.xml.remote_config_defaults);
+        mFirebaseRemoteConfig.setConfigSettingsAsync(configSettings);
+        mFirebaseRemoteConfig.setDefaultsAsync(R.xml.remote_config_defaults);
 
         displayConfig();
         displayImage();
+
+        addReadEventListener();
+
+        FCMToken();
     }
 
     private void displayImage() {
         // Create a storage reference from our app
-        StorageReference storageRef = mFirebaseStorage.getReferenceFromUrl("gs://fir-test-30d1c.appspot.com/스크린샷, 2016-11-26 00-41-42.png");
+        StorageReference storageRef = mFirebaseStorage.getReferenceFromUrl("gs://myfirebase-332e8.appspot.com/3.jpg");
         storageRef.getBytes(Long.MAX_VALUE).addOnSuccessListener(new OnSuccessListener<byte[]>() {
             @Override
             public void onSuccess(byte[] bytes) {
@@ -81,29 +90,20 @@ public void onFailure(@NonNull Exception exception) {
     }
 
     private void displayConfig() {
-        Boolean cheat_enabled = mFirebaseRemoteConfig.getBoolean("cheat_enabled");
-        ((TextView)findViewById(R.id.textView_cheat)).setText("cheat_enabled=" + cheat_enabled);
+        boolean cheat_enabled = mFirebaseRemoteConfig.getBoolean("cheat_enabled");
+        binding.textViewCheat.setText("cheat_enabled=" + cheat_enabled);
         long price = mFirebaseRemoteConfig.getLong("your_price");
-        ((TextView)findViewById(R.id.textView_price)).setText("your_price is " + price);
+        binding.textViewPrice.setText("your_price is " + price);
     }
 
     public void onFetchButton(View v) {
-        long cacheExpiration = 3600; // 1 hour in seconds.
-        // If in developer mode cacheExpiration is set to 0 so each fetch will retrieve values from
-        // the server.
-        if (mFirebaseRemoteConfig.getInfo().getConfigSettings().isDeveloperModeEnabled()) {
-            cacheExpiration = 0;
-        }
-
-        mFirebaseRemoteConfig.fetch(cacheExpiration)
-                .addOnCompleteListener(new OnCompleteListener<Void>() {
+        mFirebaseRemoteConfig.fetchAndActivate()
+                .addOnCompleteListener(this, new OnCompleteListener<Boolean>() {
                     @Override
-                    public void onComplete(@NonNull Task<Void> task) {
+                    public void onComplete(@NonNull Task<Boolean> task) {
                         if (task.isSuccessful()) {
-                            Log.d(TAG, "Fetch Succeeded");
-                            // Once the config is successfully fetched it must be activated before newly fetched
-                            // values are returned.
-                            mFirebaseRemoteConfig.activateFetched();
+                            boolean updated = task.getResult();
+                            Log.d(TAG, "Config params updated: " + updated);
                         } else {
                             Log.d(TAG, "Fetch failed");
                         }
@@ -112,6 +112,58 @@ public void onComplete(@NonNull Task<Void> task) {
                 });
     }
 
+    public void onWriteData(View v) {
+        String db_value = binding.dbValue.getText().toString();
+        FirebaseDatabase database = FirebaseDatabase.getInstance();
+        DatabaseReference myRef = database.getReference("message");
+
+        myRef.setValue(db_value);
+    }
+
+    public void addReadEventListener() {
+        FirebaseDatabase database = FirebaseDatabase.getInstance();
+        DatabaseReference myRef = database.getReference("message");
+        // Read from the database
+        myRef.addValueEventListener(new ValueEventListener() {
+            @Override
+            public void onDataChange(DataSnapshot dataSnapshot) {
+                // This method is called once with the initial value and again
+                // whenever data at this location is updated.
+                String value = dataSnapshot.getValue(String.class);
+                binding.dbValue.setText(value);
+                Toast.makeText(getApplicationContext(), "Successed to read value.", Toast.LENGTH_LONG).show();
+            }
+
+            @Override
+            public void onCancelled(DatabaseError error) {
+                // Failed to read value
+                Log.w(TAG, "Failed to read value.", error.toException());
+                Toast.makeText(getApplicationContext(), "Failed to read value.", Toast.LENGTH_LONG).show();
+            }
+        });
+    }
+
+    public void FCMToken() {
+        FirebaseInstanceId.getInstance().getInstanceId().addOnCompleteListener(new OnCompleteListener<InstanceIdResult>() {
+            @Override
+            public void onComplete(@NonNull Task<InstanceIdResult> task) {
+                if (!task.isSuccessful()) {
+                    Log.w(TAG, "getInstanceId failed", task.getException());
+                    return;
+                }
+
+                // Get new Instance ID token
+                String token = task.getResult().getToken();
+
+                // Log and toast
+                String msg = "FCM token:" + token;
+                binding.tvToken.setText(msg);
+                Log.d(TAG, msg);
+                Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
+            }
+        });
+    }
+
     public void onLogoutButton(View v) {
         mAuth.signOut();
         finish();
diff --git a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MyFirebaseInstanceIDService.java b/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MyFirebaseInstanceIDService.java
deleted file mode 100644
index d8b809f..0000000
--- a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MyFirebaseInstanceIDService.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package com.example.jyheo.firebasetest;
-
-import android.app.Service;
-import android.util.Log;
-
-import com.google.firebase.iid.FirebaseInstanceId;
-import com.google.firebase.iid.FirebaseInstanceIdService;
-
-/**
- * Created by jyheo on 16. 11. 26.
- */
-public class MyFirebaseInstanceIDService extends FirebaseInstanceIdService {
-    private static final String TAG = "MyFirebaseIIDService";
-
-    @Override
-    public void onTokenRefresh() {
-        // Get updated InstanceID token.
-        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
-        Log.d(TAG, "Refreshed token: " + refreshedToken);
-
-        // TODO: Implement this method to send any registration to your app's servers.
-        // sendRegistrationToServer(refreshedToken);
-    }
-}
diff --git a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MyFirebaseMessagingService.java b/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MyFirebaseMessagingService.java
index a653d3d..fe260c9 100644
--- a/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MyFirebaseMessagingService.java
+++ b/FirebaseTest/app/src/main/java/com/example/jyheo/firebasetest/MyFirebaseMessagingService.java
@@ -2,6 +2,8 @@
 
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+
 import com.google.firebase.messaging.FirebaseMessagingService;
 import com.google.firebase.messaging.RemoteMessage;
 
@@ -12,6 +14,15 @@
 public class MyFirebaseMessagingService extends FirebaseMessagingService {
     private static final String TAG = "MyFirebaseMsgService";
 
+    @Override
+    public void onNewToken(@NonNull String token) {
+        // Get updated InstanceID token.
+        Log.d(TAG, "Refreshed token: " + token);
+
+        // TODO: Implement this method to send any registration to your app's servers.
+        // sendRegistrationToServer(token);
+    }
+
     @Override
     public void onMessageReceived(RemoteMessage remoteMessage) {
         String msgBody = "";
diff --git a/FirebaseTest/app/src/main/res/layout/activity_main.xml b/FirebaseTest/app/src/main/res/layout/activity_main.xml
index 68ebde8..4d60133 100644
--- a/FirebaseTest/app/src/main/res/layout/activity_main.xml
+++ b/FirebaseTest/app/src/main/res/layout/activity_main.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
@@ -7,48 +7,55 @@
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
+    android:orientation="vertical"
     tools:context="com.example.jyheo.firebasetest.MainActivity">
 
     <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:textAppearance="?android:attr/textAppearanceLarge"
+        android:textAppearance="?android:attr/textAppearanceMedium"
         android:text="cheat enabled=false"
-        android:id="@+id/textView_cheat"
-        android:layout_below="@+id/button_fetch"
-        android:layout_alignParentStart="true" />
+        android:id="@+id/textView_cheat"/>
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textAppearance="?android:attr/textAppearanceMedium"
+        android:text="your price is 100"
+        android:id="@+id/textView_price" />
 
     <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Fetch Remote Config"
-        android:id="@+id/button_fetch"
-        android:layout_alignParentTop="true"
-        android:layout_alignParentStart="true"
         android:onClick="onFetchButton" />
 
-    <TextView
+    <EditText
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:id="@+id/db_value"
+        android:text="sample data"/>
+
+    <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:textAppearance="?android:attr/textAppearanceLarge"
-        android:text="your price is 100"
-        android:id="@+id/textView_price"
-        android:layout_below="@+id/textView_cheat"
-        android:layout_alignParentStart="true" />
+        android:text="Write Data"
+        android:onClick="onWriteData"/>
+
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="FCM token:"
+        android:id="@+id/tv_token" />
 
     <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Logout"
-        android:id="@+id/button_logout"
-        android:layout_below="@+id/textView_price"
-        android:layout_alignParentStart="true"
         android:onClick="onLogoutButton" />
 
     <ImageView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:id="@+id/imageView"
-        android:layout_below="@+id/button_logout"
-        android:layout_alignParentStart="true" />
-</RelativeLayout>
+        android:id="@+id/imageView" />
+</LinearLayout>
diff --git a/FirebaseTest/build.gradle b/FirebaseTest/build.gradle
index fc64aa9..fd93bb3 100644
--- a/FirebaseTest/build.gradle
+++ b/FirebaseTest/build.gradle
@@ -1,23 +1,25 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
-
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath "com.android.tools.build:gradle:4.0.0"
+        classpath 'com.google.gms:google-services:4.3.3'
+
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
-        classpath 'com.google.gms:google-services:3.0.0'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
     }
 }
 
 task clean(type: Delete) {
     delete rootProject.buildDir
-}
+}
\ No newline at end of file
diff --git a/FirebaseTest/fcm_test.sh b/FirebaseTest/fcm_test.sh
new file mode 100644
index 0000000..fe93fae
--- /dev/null
+++ b/FirebaseTest/fcm_test.sh
@@ -0,0 +1,3 @@
+KEY=AAAAgbNS69M:APA91bEnJ4_P45eG6yPYrvg3wdO6_LybNE-kzsjGUVVlsaNvUZ9nQcf3J-cm908H1eirmShT_YX-8a2_4XsuiaHoE3AbuWRVAxPXSJKKL1oBQsXWkMDFcMMhssUm23Z6U7iptNxObmrNRu5VjhCLv7oK2SPNG3xMxw
+TOKEN=ePLprMzS__c:APA91bEXPouC6CPXaXzjKF0GCvXrAADP7PVAeG9ENwFCEcD3rSxgZ8Xwx4xVV2YktgHAqGw7u155ItP_q2vpi7cwU7AlKqol8HCUzppEKQYPF2y6l3e6FvJm7_ooTokG8Tr3AieiNfVJ
+curl --header "Authorization: key=$KEY" --header Content-Type:"application/json" https://fcm.googleapis.com/fcm/send -d "{ \"notification\": { \"title\": \"title here\", \"text\": \"message body here\" }, \"to\" : \"$TOKEN\"}"
diff --git a/FirebaseTest/gradle.properties b/FirebaseTest/gradle.properties
index 1d3591c..c52ac9b 100644
--- a/FirebaseTest/gradle.properties
+++ b/FirebaseTest/gradle.properties
@@ -1,18 +1,19 @@
 # Project-wide Gradle settings.
-
 # IDE (e.g. Android Studio) users:
 # Gradle settings configured through the IDE *will override*
 # any settings specified in this file.
-
 # For more details on how to configure your build environment visit
 # http://www.gradle.org/docs/current/userguide/build_environment.html
-
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-# Default value: -Xmx10248m -XX:MaxPermSize=256m
-# org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
-
+org.gradle.jvmargs=-Xmx2048m
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
\ No newline at end of file
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app"s APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
\ No newline at end of file
diff --git a/FirebaseTest/gradle/wrapper/gradle-wrapper.properties b/FirebaseTest/gradle/wrapper/gradle-wrapper.properties
index fadd636..a78ebe6 100644
--- a/FirebaseTest/gradle/wrapper/gradle-wrapper.properties
+++ b/FirebaseTest/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Oct 23 15:28:39 KST 2017
+#Fri Jun 26 00:36:09 KST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
diff --git a/FragmentBasic/.idea/compiler.xml b/FragmentBasic/.idea/compiler.xml
deleted file mode 100644
index 96cc43e..0000000
--- a/FragmentBasic/.idea/compiler.xml
+++ /dev/null
@@ -1,22 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <resourceExtensions />
-    <wildcardResourcePatterns>
-      <entry name="!?*.java" />
-      <entry name="!?*.form" />
-      <entry name="!?*.class" />
-      <entry name="!?*.groovy" />
-      <entry name="!?*.scala" />
-      <entry name="!?*.flex" />
-      <entry name="!?*.kt" />
-      <entry name="!?*.clj" />
-      <entry name="!?*.aj" />
-    </wildcardResourcePatterns>
-    <annotationProcessing>
-      <profile default="true" name="Default" enabled="false">
-        <processorPath useClasspath="true" />
-      </profile>
-    </annotationProcessing>
-  </component>
-</project>
\ No newline at end of file
diff --git a/FragmentBasic/.idea/copyright/profiles_settings.xml b/FragmentBasic/.idea/copyright/profiles_settings.xml
deleted file mode 100644
index e7bedf3..0000000
--- a/FragmentBasic/.idea/copyright/profiles_settings.xml
+++ /dev/null
@@ -1,3 +0,0 @@
-<component name="CopyrightManager">
-  <settings default="" />
-</component>
\ No newline at end of file
diff --git a/FragmentBasic/.idea/encodings.xml b/FragmentBasic/.idea/encodings.xml
deleted file mode 100644
index 97626ba..0000000
--- a/FragmentBasic/.idea/encodings.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="Encoding">
-    <file url="PROJECT" charset="UTF-8" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/FragmentBasic/.idea/gradle.xml b/FragmentBasic/.idea/gradle.xml
index 0e23f8e..5cd135a 100644
--- a/FragmentBasic/.idea/gradle.xml
+++ b/FragmentBasic/.idea/gradle.xml
@@ -1,11 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
-        <option name="distributionType" value="LOCAL" />
+        <option name="testRunner" value="PLATFORM" />
+        <option name="distributionType" value="DEFAULT_WRAPPED" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
-        <option name="gradleHome" value="$APPLICATION_HOME_DIR$/gradle/gradle-2.14.1" />
         <option name="modules">
           <set>
             <option value="$PROJECT_DIR$" />
diff --git a/FragmentBasic/.idea/misc.xml b/FragmentBasic/.idea/misc.xml
index 9adc8c9..261489e 100644
--- a/FragmentBasic/.idea/misc.xml
+++ b/FragmentBasic/.idea/misc.xml
@@ -1,62 +1,28 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
+  <component name="CMakeSettings">
+    <configurations>
+      <configuration PROFILE_NAME="Debug" CONFIG_NAME="Debug" />
+    </configurations>
   </component>
-  <component name="NullableNotNullManager">
-    <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
-    <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
-    <option name="myNullables">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
-        </list>
-      </value>
-    </option>
-    <option name="myNotNulls">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
-        </list>
-      </value>
-    </option>
+  <component name="ProjectInspectionProfilesVisibleTreeState">
+    <entry key="Project Default">
+      <profile-state>
+        <expanded-state>
+          <State />
+        </expanded-state>
+        <selected-state>
+          <State>
+            <id>Android</id>
+          </State>
+        </selected-state>
+      </profile-state>
+    </entry>
   </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
     <option name="id" value="Android" />
   </component>
-  <component name="masterDetails">
-    <states>
-      <state key="ProjectJDKs.UI">
-        <settings>
-          <last-edited>Android API 24 Platform</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-    </states>
-  </component>
 </project>
\ No newline at end of file
diff --git a/FragmentBasic/.idea/modules.xml b/FragmentBasic/.idea/modules.xml
index f146508..5b1845c 100644
--- a/FragmentBasic/.idea/modules.xml
+++ b/FragmentBasic/.idea/modules.xml
@@ -2,8 +2,8 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/FragmentBasic.iml" filepath="$PROJECT_DIR$/FragmentBasic.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
+      <module fileurl="file://$PROJECT_DIR$/FragmentBasic.iml" filepath="$PROJECT_DIR$/FragmentBasic.iml" group="FragmentBasic" />
+      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" group="FragmentBasic/app" />
     </modules>
   </component>
 </project>
\ No newline at end of file
diff --git a/FragmentBasic/app/build.gradle b/FragmentBasic/app/build.gradle
index a5b3c96..ebad2e9 100644
--- a/FragmentBasic/app/build.gradle
+++ b/FragmentBasic/app/build.gradle
@@ -1,29 +1,34 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 24
-    buildToolsVersion "23.0.3"
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
+
     defaultConfig {
-        applicationId "com.jyheo.fragmentbasic"
-        minSdkVersion 22
-        targetSdkVersion 24
+        applicationId "com.example.fragmentbasic"
+        minSdkVersion 23
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
+
     buildTypes {
         release {
             minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    })
-    compile 'com.android.support:appcompat-v7:24.0.0'
-    testCompile 'junit:junit:4.12'
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    implementation 'androidx.fragment:fragment:1.2.4'
 }
diff --git a/FragmentBasic/app/src/main/AndroidManifest.xml b/FragmentBasic/app/src/main/AndroidManifest.xml
index f8ba09f..7a1174d 100644
--- a/FragmentBasic/app/src/main/AndroidManifest.xml
+++ b/FragmentBasic/app/src/main/AndroidManifest.xml
@@ -15,7 +15,6 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".FragSwitchActivity"></activity>
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/FirstFragment.java b/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/FirstFragment.java
index 98363c9..6fd87c6 100644
--- a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/FirstFragment.java
+++ b/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/FirstFragment.java
@@ -2,18 +2,13 @@
 
 
 import android.os.Bundle;
-import android.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import androidx.fragment.app.Fragment;
 
-
-/**
- * A simple {@link Fragment} subclass.
- */
 public class FirstFragment extends Fragment {
 
-
     public FirstFragment() {
         // Required empty public constructor
     }
diff --git a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/FragSwitchActivity.java b/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/FragSwitchActivity.java
deleted file mode 100644
index a7b0a54..0000000
--- a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/FragSwitchActivity.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package com.jyheo.fragmentbasic;
-
-import android.app.FragmentTransaction;
-import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
-import android.view.View;
-import android.widget.Button;
-
-public class FragSwitchActivity extends AppCompatActivity {
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_frag_switch);
-
-        Button button = (Button)findViewById(R.id.button_first);
-        button.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                switchFragment(0);
-            }
-        });
-        button = (Button)findViewById(R.id.button_second);
-        button.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                switchFragment(1);
-            }
-        });
-    }
-
-    final FirstFragment firstFragment = new FirstFragment();
-    final SecondFragment secondFragment = new SecondFragment();
-
-    protected void switchFragment(int id) {
-        final FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
-        if (id == 0)
-            fragmentTransaction.replace(R.id.fragment, firstFragment);
-        else
-            fragmentTransaction.replace(R.id.fragment, secondFragment);
-        fragmentTransaction.commit();
-    }
-}
diff --git a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/MainActivity.java b/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/MainActivity.java
index 0ecd15b..3528a0b 100644
--- a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/MainActivity.java
+++ b/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/MainActivity.java
@@ -1,11 +1,10 @@
 package com.jyheo.fragmentbasic;
 
-import android.support.v7.app.AppCompatActivity;
-import android.app.FragmentTransaction;
-import android.content.Intent;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.fragment.app.FragmentTransaction;
 
 public class MainActivity extends AppCompatActivity {
 
@@ -13,29 +12,28 @@ public class MainActivity extends AppCompatActivity {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-
-        final FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
-        fragmentTransaction.replace(R.id.fragment, new SecondFragment());
-        fragmentTransaction.addToBackStack(null);
-        fragmentTransaction.commit();
     }
 
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
-        //return super.onCreateOptionsMenu(menu);
         getMenuInflater().inflate(R.menu.main_menu, menu);
         return true;
     }
 
+    void switchFragment() {
+        getSupportFragmentManager()
+                .beginTransaction()
+                .replace(R.id.fragment, new SecondFragment())
+                .addToBackStack(null)
+                .commit();
+    }
+
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.frag_switch:
-                Intent intent = new Intent(this, FragSwitchActivity.class);
-                startActivity(intent);
-                return true;
-            default:
-                return super.onOptionsItemSelected(item);
+        if (item.getItemId() == R.id.frag_switch) {
+            switchFragment();
+            return true;
         }
+        return super.onOptionsItemSelected(item);
     }
 }
diff --git a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/SecondFragment.java b/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/SecondFragment.java
index 3df17cb..149910c 100644
--- a/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/SecondFragment.java
+++ b/FragmentBasic/app/src/main/java/com/jyheo/fragmentbasic/SecondFragment.java
@@ -2,15 +2,11 @@
 
 
 import android.os.Bundle;
-import android.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import androidx.fragment.app.Fragment;
 
-
-/**
- * A simple {@link Fragment} subclass.
- */
 public class SecondFragment extends Fragment {
 
 
diff --git a/FragmentBasic/app/src/main/res/layout/activity_frag_switch.xml b/FragmentBasic/app/src/main/res/layout/activity_frag_switch.xml
deleted file mode 100644
index cb7c5ed..0000000
--- a/FragmentBasic/app/src/main/res/layout/activity_frag_switch.xml
+++ /dev/null
@@ -1,35 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/activity_frag_switch"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:paddingBottom="@dimen/activity_vertical_margin"
-    android:paddingLeft="@dimen/activity_horizontal_margin"
-    android:paddingRight="@dimen/activity_horizontal_margin"
-    android:paddingTop="@dimen/activity_vertical_margin"
-    android:orientation="vertical"
-    tools:context="com.jyheo.fragmentbasic.FragSwitchActivity">
-
-    <LinearLayout
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:orientation="horizontal">
-        <Button
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="FirstFrag"
-            android:id="@+id/button_first"/>
-        <Button
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="SecondFrag"
-            android:id="@+id/button_second"/>
-    </LinearLayout>
-    <FrameLayout
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:background="#ff00ff"
-        android:id="@+id/fragment">
-    </FrameLayout>
-</LinearLayout>
diff --git a/FragmentBasic/app/src/main/res/layout/activity_main.xml b/FragmentBasic/app/src/main/res/layout/activity_main.xml
index c56717b..d08a35b 100644
--- a/FragmentBasic/app/src/main/res/layout/activity_main.xml
+++ b/FragmentBasic/app/src/main/res/layout/activity_main.xml
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/activity_main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
@@ -12,17 +11,11 @@
         android:layout_height="wrap_content"
         android:text="Hello World!" />
 
-    <FrameLayout
+    <androidx.fragment.app.FragmentContainerView
+        android:id="@+id/fragment"
+        android:name="com.jyheo.fragmentbasic.FirstFragment"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:id="@+id/fragment">
-
-        <fragment
-            android:name="com.jyheo.fragmentbasic.FirstFragment"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"/>
-
-    </FrameLayout>
-
+        android:layout_height="0dp"
+        android:layout_weight="1" />
     
 </LinearLayout>
diff --git a/FragmentBasic/build.gradle b/FragmentBasic/build.gradle
index 74b2ab0..be0f7ca 100644
--- a/FragmentBasic/build.gradle
+++ b/FragmentBasic/build.gradle
@@ -1,11 +1,15 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+    
     repositories {
+        google()
         jcenter()
+        
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.3'
+        classpath 'com.android.tools.build:gradle:4.0.0'
+        
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -14,7 +18,9 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
+        
     }
 }
 
diff --git a/FragmentBasic/gradle.properties b/FragmentBasic/gradle.properties
index aac7c9b..199d16e 100644
--- a/FragmentBasic/gradle.properties
+++ b/FragmentBasic/gradle.properties
@@ -1,17 +1,20 @@
 # Project-wide Gradle settings.
-
 # IDE (e.g. Android Studio) users:
 # Gradle settings configured through the IDE *will override*
 # any settings specified in this file.
-
 # For more details on how to configure your build environment visit
 # http://www.gradle.org/docs/current/userguide/build_environment.html
-
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
 org.gradle.jvmargs=-Xmx1536m
-
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
+
diff --git a/FragmentBasic/gradle/wrapper/gradle-wrapper.jar b/FragmentBasic/gradle/wrapper/gradle-wrapper.jar
index 13372ae..f6b961f 100644
Binary files a/FragmentBasic/gradle/wrapper/gradle-wrapper.jar and b/FragmentBasic/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/FragmentBasic/gradle/wrapper/gradle-wrapper.properties b/FragmentBasic/gradle/wrapper/gradle-wrapper.properties
index 04e285f..173949c 100644
--- a/FragmentBasic/gradle/wrapper/gradle-wrapper.properties
+++ b/FragmentBasic/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Dec 28 10:00:20 PST 2015
+#Sat May 30 02:05:31 KST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
diff --git a/FragmentExample/.idea/gradle.xml b/FragmentExample/.idea/gradle.xml
index fe72da5..4d4b00d 100644
--- a/FragmentExample/.idea/gradle.xml
+++ b/FragmentExample/.idea/gradle.xml
@@ -1,8 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
+        <option name="testRunner" value="PLATFORM" />
         <option name="distributionType" value="LOCAL" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
         <option name="gradleHome" value="C:\Program Files\Android\Android Studio\gradle\gradle-2.14.1" />
diff --git a/FragmentExample/.idea/misc.xml b/FragmentExample/.idea/misc.xml
index 6c50245..1ff7cbb 100644
--- a/FragmentExample/.idea/misc.xml
+++ b/FragmentExample/.idea/misc.xml
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
-  </component>
   <component name="MarkdownProjectSettings">
     <PreviewSettings splitEditorLayout="SPLIT" splitEditorPreview="PREVIEW" useGrayscaleRendering="false" zoomFactor="1.0" maxImageWidth="0" showGitHubPageIfSynced="false" allowBrowsingInPreview="false" synchronizePreviewPosition="true" highlightPreviewType="LINE" highlightFadeOut="5" highlightOnTyping="true" synchronizeSourcePosition="true">
       <PanelProvider>
@@ -69,39 +66,44 @@
   </component>
   <component name="NullableNotNullManager">
     <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
-    <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
+    <option name="myDefaultNotNull" value="androidx.annotation.NonNull" />
     <option name="myNullables">
       <value>
-        <list size="4">
+        <list size="12">
           <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
           <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
           <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
           <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
+          <item index="4" class="java.lang.String" itemvalue="javax.annotation.CheckForNull" />
+          <item index="5" class="java.lang.String" itemvalue="androidx.annotation.Nullable" />
+          <item index="6" class="java.lang.String" itemvalue="android.annotation.Nullable" />
+          <item index="7" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNullable" />
+          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />
+          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
+          <item index="10" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
+          <item index="11" class="java.lang.String" itemvalue="com.android.annotations.Nullable" />
         </list>
       </value>
     </option>
     <option name="myNotNulls">
       <value>
-        <list size="4">
+        <list size="11">
           <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
           <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
           <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
           <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
+          <item index="4" class="java.lang.String" itemvalue="androidx.annotation.NonNull" />
+          <item index="5" class="java.lang.String" itemvalue="android.annotation.NonNull" />
+          <item index="6" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNonNull" />
+          <item index="7" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.NonNull" />
+          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullDecl" />
+          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullType" />
+          <item index="10" class="java.lang.String" itemvalue="com.android.annotations.NonNull" />
         </list>
       </value>
     </option>
   </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/FragmentExample/.idea/modules.xml b/FragmentExample/.idea/modules.xml
index 419490f..dcedca9 100644
--- a/FragmentExample/.idea/modules.xml
+++ b/FragmentExample/.idea/modules.xml
@@ -2,8 +2,8 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/FragmentExample.iml" filepath="$PROJECT_DIR$/FragmentExample.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
+      <module fileurl="file://$PROJECT_DIR$/FragmentExample.iml" filepath="$PROJECT_DIR$/FragmentExample.iml" group="FragmentExample" />
+      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" group="FragmentExample/app" />
     </modules>
   </component>
 </project>
\ No newline at end of file
diff --git a/FragmentExample/app/build.gradle b/FragmentExample/app/build.gradle
index 68c2b4a..ebfc4a4 100644
--- a/FragmentExample/app/build.gradle
+++ b/FragmentExample/app/build.gradle
@@ -1,27 +1,43 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 24
-    buildToolsVersion "24.0.0"
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
 
     defaultConfig {
-        applicationId "com.jyheo.fragmentexample"
-        minSdkVersion 22
-        targetSdkVersion 24
+        applicationId "com.example.fragmentexample"
+        minSdkVersion 23
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
+
     buildTypes {
         release {
             minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
+
+    buildFeatures {
+        viewBinding true
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    compile 'com.android.support:appcompat-v7:24.2.1'
-    compile 'com.android.support:support-v4:24.2.1'
-    testCompile 'junit:junit:4.12'
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
 }
diff --git a/FragmentExample/app/src/main/AndroidManifest.xml b/FragmentExample/app/src/main/AndroidManifest.xml
index 09e86b1..d16acd7 100644
--- a/FragmentExample/app/src/main/AndroidManifest.xml
+++ b/FragmentExample/app/src/main/AndroidManifest.xml
@@ -15,7 +15,6 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".DetailsActivity"></activity>
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/DetailsActivity.java b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/DetailsActivity.java
deleted file mode 100644
index d29e450..0000000
--- a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/DetailsActivity.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package com.jyheo.fragmentexample;
-
-import android.app.Activity;
-import android.content.res.Configuration;
-import android.os.Bundle;
-
-public class DetailsActivity extends Activity {
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_details);
-
-        if (getResources().getConfiguration().orientation
-                == Configuration.ORIENTATION_LANDSCAPE) {
-            finish();
-            return;
-        }
-
-        DetailsFragment details = new DetailsFragment();
-        details.setArguments(getIntent().getExtras());
-        getFragmentManager().beginTransaction().replace(R.id.details, details).commit();
-    }
-}
diff --git a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/DetailsFragment.java b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/DetailsFragment.java
index 68f4309..49479f4 100644
--- a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/DetailsFragment.java
+++ b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/DetailsFragment.java
@@ -2,45 +2,36 @@
 
 
 import android.os.Bundle;
-import android.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.TextView;
 
+import androidx.annotation.NonNull;
+import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
 
-/**
- * A simple {@link Fragment} subclass.
- */
-public class DetailsFragment extends Fragment {
-
-
-    public DetailsFragment() {
-        // Required empty public constructor
-    }
-
-    public static DetailsFragment newInstance(int index) {
-        DetailsFragment f = new DetailsFragment();
+import com.jyheo.fragmentexample.databinding.FragmentDetailsBinding;
 
-        // Supply index input as an argument.
-        Bundle args = new Bundle();
-        args.putInt("index", index);
-        f.setArguments(args);
 
-        return f;
-    }
+public class DetailsFragment extends Fragment {
+    private FragmentDetailsBinding binding;
 
+    public DetailsFragment() { }
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
-        // Inflate the layout for this fragment
-        View view = inflater.inflate(R.layout.fragment_details, container, false);
-        int i = getArguments().getInt("index", 0);
-        TextView tv = (TextView)view.findViewById(R.id.textview);
-        tv.setText(Shakespeare.DIALOGUE[i]);
-
-        return view;
+        binding = FragmentDetailsBinding.inflate(inflater, container, false);
+        return binding.getRoot();
     }
 
+    @Override
+    public void onStart() {
+        super.onStart();
+        MyViewModel model = new ViewModelProvider(requireActivity()).get(MyViewModel.class);
+        model.getSelected().observe(this, idx -> {
+            if (idx >= 0)
+                binding.textview.setText(Shakespeare.DIALOGUE[idx]);
+        });
+    }
 }
diff --git a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/MainActivity.java b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/MainActivity.java
index d9037b0..e5cc6d7 100644
--- a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/MainActivity.java
+++ b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/MainActivity.java
@@ -1,50 +1,13 @@
 package com.jyheo.fragmentexample;
 
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import android.support.v7.app.AppCompatActivity;
-import android.content.Intent;
-import android.content.res.Configuration;
 import android.os.Bundle;
+import androidx.appcompat.app.AppCompatActivity;
 
-public class MainActivity extends AppCompatActivity implements TitlesFragment.OnTitleSelectedListener{
-
-    boolean mbDetailsVisible = false;
+public class MainActivity extends AppCompatActivity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        if (findViewById(R.id.details) != null)
-            mbDetailsVisible = true;
-        else
-            mbDetailsVisible = false;
-    }
-
-    public void onTitleSelected(int i, boolean restoreSaved) {
-        if (mbDetailsVisible) {
-            DetailsFragment detailsFragment = DetailsFragment.newInstance(i);
-            getFragmentManager().beginTransaction().replace(R.id.details, detailsFragment).commit();
-        } else {
-            if (restoreSaved == false) {
-                Intent intent = new Intent(this, DetailsActivity.class);
-                intent.putExtra("index", i);
-                startActivity(intent);
-            }
-        }
     }
 }
diff --git a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/MyViewModel.java b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/MyViewModel.java
new file mode 100644
index 0000000..441b435
--- /dev/null
+++ b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/MyViewModel.java
@@ -0,0 +1,22 @@
+package com.jyheo.fragmentexample;
+
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+public class MyViewModel extends ViewModel {
+
+    private final MutableLiveData<Integer> selected = new MutableLiveData<>();
+
+    public MyViewModel() {
+        selected.setValue(-1);
+    }
+
+    public void select(Integer item) {
+        selected.setValue(item);
+    }
+
+    public LiveData<Integer> getSelected() {
+        return selected;
+    }
+}
diff --git a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/TitlesFragment.java b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/TitlesFragment.java
index 8f33891..25619f1 100644
--- a/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/TitlesFragment.java
+++ b/FragmentExample/app/src/main/java/com/jyheo/fragmentexample/TitlesFragment.java
@@ -2,7 +2,7 @@
 
 
 import android.os.Bundle;
-import android.app.Fragment;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -10,62 +10,32 @@
 import android.widget.ArrayAdapter;
 import android.widget.ListView;
 
+import androidx.annotation.NonNull;
+import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
 
-/**
- * A simple {@link Fragment} subclass.
- */
-public class TitlesFragment extends Fragment {
+import com.jyheo.fragmentexample.databinding.FragmentTitlesBinding;
 
-    int mCurCheckPosition = -1;
 
-    public TitlesFragment() {
-        // Required empty public constructor
-    }
+public class TitlesFragment extends Fragment {
 
-    @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container,
-                             Bundle savedInstanceState) {
-        // Inflate the layout for this fragment
-        return inflater.inflate(R.layout.fragment_titles, container, false);
-    }
+    private FragmentTitlesBinding binding;
+    private MyViewModel model;
 
-    public interface OnTitleSelectedListener {
-        public void onTitleSelected(int i, boolean restoreSaved);
-    }
+    public TitlesFragment() { }
 
     @Override
-    public void onActivityCreated(Bundle savedInstanceState) {
-        super.onActivityCreated(savedInstanceState);
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
+                             Bundle savedInstanceState) {
+        binding = FragmentTitlesBinding.inflate(inflater, container, false);
 
-        ListView lv = (ListView)getView().findViewById(R.id.listview);
+        model = new ViewModelProvider(requireActivity()).get(MyViewModel.class);
 
-        lv.setAdapter(new ArrayAdapter<String>(getActivity(),
+        binding.listview.setAdapter(new ArrayAdapter<>(requireContext(),
                 android.R.layout.simple_list_item_activated_1, Shakespeare.TITLES));
-        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
-            @Override
-            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
-                mCurCheckPosition = i;
+        binding.listview.setOnItemClickListener((adapterView, view, i, l) -> model.select(i));
+        binding.listview.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
 
-                ((OnTitleSelectedListener)getActivity()).onTitleSelected(i, false);
-            }
-        });
-
-        lv.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
-
-        if (savedInstanceState != null) {
-            mCurCheckPosition = savedInstanceState.getInt("curChoice", -1);
-            if (mCurCheckPosition >= 0)
-                ((OnTitleSelectedListener)getActivity()).onTitleSelected(mCurCheckPosition, true);
-        }
-
-        lv.setSelection(mCurCheckPosition);
-        lv.smoothScrollToPosition(mCurCheckPosition);
+        return binding.getRoot();
     }
-
-    @Override
-    public void onSaveInstanceState(Bundle outState) {
-        super.onSaveInstanceState(outState);
-        outState.putInt("curChoice", mCurCheckPosition);
-    }
-
 }
diff --git a/FragmentExample/app/src/main/res/layout-land/activity_main.xml b/FragmentExample/app/src/main/res/layout-land/activity_main.xml
index 9124918..9633401 100644
--- a/FragmentExample/app/src/main/res/layout-land/activity_main.xml
+++ b/FragmentExample/app/src/main/res/layout-land/activity_main.xml
@@ -4,17 +4,23 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
-    <fragment
+    <androidx.fragment.app.FragmentContainerView
         android:name="com.jyheo.fragmentexample.TitlesFragment"
         android:id="@+id/titles"
         android:layout_weight="1"
-        android:layout_width="0px"
+        android:layout_width="0dp"
         android:layout_height="match_parent" />
 
-    <FrameLayout
+    <View
+        android:layout_width="5dp"
+        android:layout_height="match_parent"
+        android:background="#3F51B5" />
+
+    <androidx.fragment.app.FragmentContainerView
+        android:name="com.jyheo.fragmentexample.DetailsFragment"
         android:id="@+id/details"
         android:layout_weight="2"
-        android:layout_width="0px"
+        android:layout_width="0dp"
         android:layout_height="match_parent" />
 
 </LinearLayout>
\ No newline at end of file
diff --git a/FragmentExample/app/src/main/res/layout-large/activity_main.xml b/FragmentExample/app/src/main/res/layout-large/activity_main.xml
deleted file mode 100644
index 9124918..0000000
--- a/FragmentExample/app/src/main/res/layout-large/activity_main.xml
+++ /dev/null
@@ -1,20 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    android:orientation="horizontal"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent">
-
-    <fragment
-        android:name="com.jyheo.fragmentexample.TitlesFragment"
-        android:id="@+id/titles"
-        android:layout_weight="1"
-        android:layout_width="0px"
-        android:layout_height="match_parent" />
-
-    <FrameLayout
-        android:id="@+id/details"
-        android:layout_weight="2"
-        android:layout_width="0px"
-        android:layout_height="match_parent" />
-
-</LinearLayout>
\ No newline at end of file
diff --git a/FragmentExample/app/src/main/res/layout/activity_main.xml b/FragmentExample/app/src/main/res/layout/activity_main.xml
index 5a32af7..4a26056 100644
--- a/FragmentExample/app/src/main/res/layout/activity_main.xml
+++ b/FragmentExample/app/src/main/res/layout/activity_main.xml
@@ -4,10 +4,23 @@
     android:layout_height="match_parent"
     android:orientation="vertical">
 
-    <fragment
+    <androidx.fragment.app.FragmentContainerView
         android:name="com.jyheo.fragmentexample.TitlesFragment"
         android:id="@+id/titles"
         android:layout_width="match_parent"
-        android:layout_height="match_parent" />
+        android:layout_height="0dp"
+        android:layout_weight="1" />
+
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="5dp"
+        android:background="#3F51B5" />
+
+    <androidx.fragment.app.FragmentContainerView
+        android:name="com.jyheo.fragmentexample.DetailsFragment"
+        android:id="@+id/details"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1" />
 
 </LinearLayout>
diff --git a/FragmentExample/app/src/main/res/layout/fragment_details.xml b/FragmentExample/app/src/main/res/layout/fragment_details.xml
index f817b86..72cc60f 100644
--- a/FragmentExample/app/src/main/res/layout/fragment_details.xml
+++ b/FragmentExample/app/src/main/res/layout/fragment_details.xml
@@ -1,17 +1,13 @@
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:padding="5dp"
     tools:context="com.jyheo.fragmentexample.DetailsFragment">
 
-    <ScrollView
+    <TextView
         android:layout_width="match_parent"
-        android:layout_height="match_parent">
-        <TextView
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:text="@string/hello_blank_fragment"
-            android:id="@+id/textview"/>
-    </ScrollView>
-</LinearLayout>
+        android:layout_height="wrap_content"
+        android:text="@string/hello_blank_fragment"
+        android:id="@+id/textview"/>
+</ScrollView>
diff --git a/FragmentExample/build.gradle b/FragmentExample/build.gradle
index c20bca1..4dc1795 100644
--- a/FragmentExample/build.gradle
+++ b/FragmentExample/build.gradle
@@ -2,10 +2,11 @@
 
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.2'
+        classpath 'com.android.tools.build:gradle:4.0.0'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -14,6 +15,7 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
     }
 }
diff --git a/FragmentExample/gradle.properties b/FragmentExample/gradle.properties
index 1d3591c..199d16e 100644
--- a/FragmentExample/gradle.properties
+++ b/FragmentExample/gradle.properties
@@ -1,18 +1,20 @@
 # Project-wide Gradle settings.
-
 # IDE (e.g. Android Studio) users:
 # Gradle settings configured through the IDE *will override*
 # any settings specified in this file.
-
 # For more details on how to configure your build environment visit
 # http://www.gradle.org/docs/current/userguide/build_environment.html
-
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-# Default value: -Xmx10248m -XX:MaxPermSize=256m
-# org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
-
+org.gradle.jvmargs=-Xmx1536m
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
\ No newline at end of file
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
+
diff --git a/FragmentExample/gradle/wrapper/gradle-wrapper.jar b/FragmentExample/gradle/wrapper/gradle-wrapper.jar
index 13372ae..f6b961f 100644
Binary files a/FragmentExample/gradle/wrapper/gradle-wrapper.jar and b/FragmentExample/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/FragmentExample/gradle/wrapper/gradle-wrapper.properties b/FragmentExample/gradle/wrapper/gradle-wrapper.properties
index e3bc38a..8a269ee 100644
--- a/FragmentExample/gradle/wrapper/gradle-wrapper.properties
+++ b/FragmentExample/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Thu Sep 29 23:16:10 KST 2016
+#Sat May 30 01:52:06 KST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
diff --git a/LocationAware/.gitignore b/InstantAppTest/.gitignore
similarity index 82%
rename from LocationAware/.gitignore
rename to InstantAppTest/.gitignore
index c6cbe56..39fb081 100644
--- a/LocationAware/.gitignore
+++ b/InstantAppTest/.gitignore
@@ -6,3 +6,4 @@
 .DS_Store
 /build
 /captures
+.externalNativeBuild
diff --git a/LocationAware/app/.gitignore b/InstantAppTest/app/.gitignore
similarity index 100%
rename from LocationAware/app/.gitignore
rename to InstantAppTest/app/.gitignore
diff --git a/InstantAppTest/app/build.gradle b/InstantAppTest/app/build.gradle
new file mode 100644
index 0000000..9b28ce8
--- /dev/null
+++ b/InstantAppTest/app/build.gradle
@@ -0,0 +1,31 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 26
+    
+
+
+    defaultConfig {
+        applicationId "com.example.jyheo.instantapptest"
+        minSdkVersion 23
+        targetSdkVersion 26
+        versionCode 1
+        versionName "1.0"
+
+
+    }
+
+    buildTypes {
+       release {
+           minifyEnabled false
+           proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+       }
+    }
+
+}
+
+dependencies {
+    implementation project(':feature')
+    implementation project(':feature2')
+    implementation project(':base')
+}
diff --git a/InstantAppTest/app/src/main/AndroidManifest.xml b/InstantAppTest/app/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..81badb0
--- /dev/null
+++ b/InstantAppTest/app/src/main/AndroidManifest.xml
@@ -0,0 +1,2 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.jyheo.instantapptest.app" />
diff --git a/MaterialTest/app/.gitignore b/InstantAppTest/base/.gitignore
similarity index 100%
rename from MaterialTest/app/.gitignore
rename to InstantAppTest/base/.gitignore
diff --git a/InstantAppTest/base/build.gradle b/InstantAppTest/base/build.gradle
new file mode 100644
index 0000000..55f1194
--- /dev/null
+++ b/InstantAppTest/base/build.gradle
@@ -0,0 +1,26 @@
+apply plugin: 'com.android.feature'
+
+android {
+    compileSdkVersion 26
+    baseFeature true
+    defaultConfig {
+        minSdkVersion 23
+        targetSdkVersion 26
+        versionCode 1
+        versionName "1.0"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    api 'com.android.support:appcompat-v7:26.1.0'
+    api 'com.android.support.constraint:constraint-layout:1.0.2'
+    application project(':app')
+    feature project(':feature')
+    feature project(":feature2")
+}
diff --git a/InstantAppTest/base/src/main/AndroidManifest.xml b/InstantAppTest/base/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..2917fee
--- /dev/null
+++ b/InstantAppTest/base/src/main/AndroidManifest.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.jyheo.instantapptest">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <meta-data
+            android:name="aia-compat-api-min-version"
+            android:value="1" />
+    </application>
+
+</manifest>
\ No newline at end of file
diff --git a/InstantAppTest/base/src/main/res/drawable-v24/ic_launcher_foreground.xml b/InstantAppTest/base/src/main/res/drawable-v24/ic_launcher_foreground.xml
new file mode 100644
index 0000000..c7bd21d
--- /dev/null
+++ b/InstantAppTest/base/src/main/res/drawable-v24/ic_launcher_foreground.xml
@@ -0,0 +1,34 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+    <path
+        android:fillType="evenOdd"
+        android:pathData="M32,64C32,64 38.39,52.99 44.13,50.95C51.37,48.37 70.14,49.57 70.14,49.57L108.26,87.69L108,109.01L75.97,107.97L32,64Z"
+        android:strokeColor="#00000000"
+        android:strokeWidth="1">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="78.5885"
+                android:endY="90.9159"
+                android:startX="48.7653"
+                android:startY="61.0927"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M66.94,46.02L66.94,46.02C72.44,50.07 76,56.61 76,64L32,64C32,56.61 35.56,50.11 40.98,46.06L36.18,41.19C35.45,40.45 35.45,39.3 36.18,38.56C36.91,37.81 38.05,37.81 38.78,38.56L44.25,44.05C47.18,42.57 50.48,41.71 54,41.71C57.48,41.71 60.78,42.57 63.68,44.05L69.11,38.56C69.84,37.81 70.98,37.81 71.71,38.56C72.44,39.3 72.44,40.45 71.71,41.19L66.94,46.02ZM62.94,56.92C64.08,56.92 65,56.01 65,54.88C65,53.76 64.08,52.85 62.94,52.85C61.8,52.85 60.88,53.76 60.88,54.88C60.88,56.01 61.8,56.92 62.94,56.92ZM45.06,56.92C46.2,56.92 47.13,56.01 47.13,54.88C47.13,53.76 46.2,52.85 45.06,52.85C43.92,52.85 43,53.76 43,54.88C43,56.01 43.92,56.92 45.06,56.92Z"
+        android:strokeColor="#00000000"
+        android:strokeWidth="1" />
+</vector>
diff --git a/InstantAppTest/base/src/main/res/drawable/ic_launcher_background.xml b/InstantAppTest/base/src/main/res/drawable/ic_launcher_background.xml
new file mode 100644
index 0000000..d5fccc5
--- /dev/null
+++ b/InstantAppTest/base/src/main/res/drawable/ic_launcher_background.xml
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+    <path
+        android:fillColor="#26A69A"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+</vector>
diff --git a/InstantAppTest/base/src/main/res/mipmap-anydpi-v26/ic_launcher.xml b/InstantAppTest/base/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/InstantAppTest/base/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/InstantAppTest/base/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml b/InstantAppTest/base/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/InstantAppTest/base/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/InstantAppTest/base/src/main/res/mipmap-hdpi/ic_launcher.png b/InstantAppTest/base/src/main/res/mipmap-hdpi/ic_launcher.png
new file mode 100644
index 0000000..a2f5908
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-hdpi/ic_launcher.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-hdpi/ic_launcher_round.png b/InstantAppTest/base/src/main/res/mipmap-hdpi/ic_launcher_round.png
new file mode 100644
index 0000000..1b52399
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-hdpi/ic_launcher_round.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-mdpi/ic_launcher.png b/InstantAppTest/base/src/main/res/mipmap-mdpi/ic_launcher.png
new file mode 100644
index 0000000..ff10afd
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-mdpi/ic_launcher.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-mdpi/ic_launcher_round.png b/InstantAppTest/base/src/main/res/mipmap-mdpi/ic_launcher_round.png
new file mode 100644
index 0000000..115a4c7
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-mdpi/ic_launcher_round.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-xhdpi/ic_launcher.png b/InstantAppTest/base/src/main/res/mipmap-xhdpi/ic_launcher.png
new file mode 100644
index 0000000..dcd3cd8
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-xhdpi/ic_launcher.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-xhdpi/ic_launcher_round.png b/InstantAppTest/base/src/main/res/mipmap-xhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..459ca60
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-xhdpi/ic_launcher_round.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-xxhdpi/ic_launcher.png b/InstantAppTest/base/src/main/res/mipmap-xxhdpi/ic_launcher.png
new file mode 100644
index 0000000..8ca12fe
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-xxhdpi/ic_launcher.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-xxhdpi/ic_launcher_round.png b/InstantAppTest/base/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..8e19b41
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-xxhdpi/ic_launcher_round.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/InstantAppTest/base/src/main/res/mipmap-xxxhdpi/ic_launcher.png
new file mode 100644
index 0000000..b824ebd
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ
diff --git a/InstantAppTest/base/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png b/InstantAppTest/base/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..4c19a13
Binary files /dev/null and b/InstantAppTest/base/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png differ
diff --git a/LocationAware/app/src/main/res/values/colors.xml b/InstantAppTest/base/src/main/res/values/colors.xml
similarity index 100%
rename from LocationAware/app/src/main/res/values/colors.xml
rename to InstantAppTest/base/src/main/res/values/colors.xml
diff --git a/InstantAppTest/base/src/main/res/values/strings.xml b/InstantAppTest/base/src/main/res/values/strings.xml
new file mode 100644
index 0000000..278e25a
--- /dev/null
+++ b/InstantAppTest/base/src/main/res/values/strings.xml
@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">InstantAppTest</string>
+</resources>
diff --git a/LocationAware/app/src/main/res/values/styles.xml b/InstantAppTest/base/src/main/res/values/styles.xml
similarity index 100%
rename from LocationAware/app/src/main/res/values/styles.xml
rename to InstantAppTest/base/src/main/res/values/styles.xml
diff --git a/InstantAppTest/build.gradle b/InstantAppTest/build.gradle
new file mode 100644
index 0000000..e6b32bc
--- /dev/null
+++ b/InstantAppTest/build.gradle
@@ -0,0 +1,27 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+
+buildscript {
+    
+    repositories {
+        google()
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.0.1'
+        
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}
diff --git a/InstantAppTest/feature/.gitignore b/InstantAppTest/feature/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/InstantAppTest/feature/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/InstantAppTest/feature/build.gradle b/InstantAppTest/feature/build.gradle
new file mode 100644
index 0000000..3e6f699
--- /dev/null
+++ b/InstantAppTest/feature/build.gradle
@@ -0,0 +1,27 @@
+apply plugin: 'com.android.feature'
+
+android {
+    compileSdkVersion 26
+    defaultConfig {
+        minSdkVersion 23
+        targetSdkVersion 26
+        versionCode 1
+        versionName "1.0"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation project(':base')
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'com.android.support.test:runner:1.0.1'
+    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
+    
+}
diff --git a/InstantAppTest/feature/proguard-rules.pro b/InstantAppTest/feature/proguard-rules.pro
new file mode 100644
index 0000000..f1b4245
--- /dev/null
+++ b/InstantAppTest/feature/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
diff --git a/InstantAppTest/feature/src/androidTest/java/com/example/jyheo/instantapptest/feature/ExampleInstrumentedTest.java b/InstantAppTest/feature/src/androidTest/java/com/example/jyheo/instantapptest/feature/ExampleInstrumentedTest.java
new file mode 100644
index 0000000..f760831
--- /dev/null
+++ b/InstantAppTest/feature/src/androidTest/java/com/example/jyheo/instantapptest/feature/ExampleInstrumentedTest.java
@@ -0,0 +1,26 @@
+package com.example.jyheo.instantapptest.feature;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() throws Exception {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getTargetContext();
+
+        assertEquals("com.example.jyheo.instantapptest.feature.test", appContext.getPackageName());
+    }
+}
diff --git a/InstantAppTest/feature/src/main/AndroidManifest.xml b/InstantAppTest/feature/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..443172f
--- /dev/null
+++ b/InstantAppTest/feature/src/main/AndroidManifest.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.jyheo.instantapptest.feature">
+
+    <application>
+        <activity android:name=".MainActivity">
+            <intent-filter android:order="1">
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.BROWSABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+
+                <data
+                    android:host="example.com"
+                    android:pathPattern="/hello"
+                    android:scheme="https" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file
diff --git a/InstantAppTest/feature/src/main/java/com/example/jyheo/instantapptest/feature/MainActivity.java b/InstantAppTest/feature/src/main/java/com/example/jyheo/instantapptest/feature/MainActivity.java
new file mode 100644
index 0000000..0c265ad
--- /dev/null
+++ b/InstantAppTest/feature/src/main/java/com/example/jyheo/instantapptest/feature/MainActivity.java
@@ -0,0 +1,26 @@
+package com.example.jyheo.instantapptest.feature;
+
+import android.content.Intent;
+import android.net.Uri;
+import android.support.v7.app.AppCompatActivity;
+import android.os.Bundle;
+import android.view.View;
+
+public class MainActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+        findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                Intent intent = new Intent(Intent.ACTION_VIEW,
+                        Uri.parse("https://example.com/hello2"));
+                intent.setPackage(getPackageName());
+                intent.addCategory(Intent.CATEGORY_BROWSABLE);
+                startActivity(intent);
+            }
+        });
+    }
+}
diff --git a/InstantAppTest/feature/src/main/res/layout/activity_main.xml b/InstantAppTest/feature/src/main/res/layout/activity_main.xml
new file mode 100644
index 0000000..c8a1f13
--- /dev/null
+++ b/InstantAppTest/feature/src/main/res/layout/activity_main.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context="com.example.jyheo.instantapptest.feature.MainActivity">
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Hello World! Feature 1"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <Button
+        android:id="@+id/button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="179dp"
+        android:layout_marginEnd="128dp"
+        android:layout_marginStart="129dp"
+        android:layout_marginTop="19dp"
+        android:text="Run Feature 2"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textView" />
+
+</android.support.constraint.ConstraintLayout>
diff --git a/InstantAppTest/feature/src/main/res/values/strings.xml b/InstantAppTest/feature/src/main/res/values/strings.xml
new file mode 100644
index 0000000..7abc06d
--- /dev/null
+++ b/InstantAppTest/feature/src/main/res/values/strings.xml
@@ -0,0 +1 @@
+<resources></resources>
diff --git a/InstantAppTest/feature/src/test/java/com/example/jyheo/instantapptest/feature/ExampleUnitTest.java b/InstantAppTest/feature/src/test/java/com/example/jyheo/instantapptest/feature/ExampleUnitTest.java
new file mode 100644
index 0000000..86f4e8e
--- /dev/null
+++ b/InstantAppTest/feature/src/test/java/com/example/jyheo/instantapptest/feature/ExampleUnitTest.java
@@ -0,0 +1,17 @@
+package com.example.jyheo.instantapptest.feature;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+public class ExampleUnitTest {
+    @Test
+    public void addition_isCorrect() throws Exception {
+        assertEquals(4, 2 + 2);
+    }
+}
\ No newline at end of file
diff --git a/InstantAppTest/feature2/.gitignore b/InstantAppTest/feature2/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/InstantAppTest/feature2/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/InstantAppTest/feature2/build.gradle b/InstantAppTest/feature2/build.gradle
new file mode 100644
index 0000000..a0ce10c
--- /dev/null
+++ b/InstantAppTest/feature2/build.gradle
@@ -0,0 +1,34 @@
+apply plugin: 'com.android.feature'
+
+android {
+    compileSdkVersion 26
+
+
+
+    defaultConfig {
+        minSdkVersion 23
+        targetSdkVersion 26
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation project(':base')
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'com.android.support.test:runner:1.0.1'
+    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
+}
diff --git a/InstantAppTest/feature2/proguard-rules.pro b/InstantAppTest/feature2/proguard-rules.pro
new file mode 100644
index 0000000..f1b4245
--- /dev/null
+++ b/InstantAppTest/feature2/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
diff --git a/InstantAppTest/feature2/src/androidTest/java/com/example/instantapptest/ExampleInstrumentedTest.java b/InstantAppTest/feature2/src/androidTest/java/com/example/instantapptest/ExampleInstrumentedTest.java
new file mode 100644
index 0000000..2188652
--- /dev/null
+++ b/InstantAppTest/feature2/src/androidTest/java/com/example/instantapptest/ExampleInstrumentedTest.java
@@ -0,0 +1,26 @@
+package com.example.instantapptest;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() throws Exception {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getTargetContext();
+
+        assertEquals("com.example.instantapptest.test", appContext.getPackageName());
+    }
+}
diff --git a/InstantAppTest/feature2/src/main/AndroidManifest.xml b/InstantAppTest/feature2/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..99c5172
--- /dev/null
+++ b/InstantAppTest/feature2/src/main/AndroidManifest.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.instantapptest">
+
+    <application>
+        <activity android:name=".MainActivity">
+            <intent-filter android:order="1">
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.BROWSABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+
+                <data
+                    android:host="example.com"
+                    android:pathPattern="/hello2"
+                    android:scheme="https" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file
diff --git a/InstantAppTest/feature2/src/main/java/com/example/instantapptest/MainActivity.java b/InstantAppTest/feature2/src/main/java/com/example/instantapptest/MainActivity.java
new file mode 100644
index 0000000..e4803fc
--- /dev/null
+++ b/InstantAppTest/feature2/src/main/java/com/example/instantapptest/MainActivity.java
@@ -0,0 +1,13 @@
+package com.example.instantapptest;
+
+import android.support.v7.app.AppCompatActivity;
+import android.os.Bundle;
+
+public class MainActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+    }
+}
diff --git a/InstantAppTest/feature2/src/main/res/layout/activity_main.xml b/InstantAppTest/feature2/src/main/res/layout/activity_main.xml
new file mode 100644
index 0000000..530a567
--- /dev/null
+++ b/InstantAppTest/feature2/src/main/res/layout/activity_main.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context="com.example.instantapptest.MainActivity">
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Hello World! Feature 2"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+</android.support.constraint.ConstraintLayout>
diff --git a/InstantAppTest/feature2/src/main/res/values/strings.xml b/InstantAppTest/feature2/src/main/res/values/strings.xml
new file mode 100644
index 0000000..f11f745
--- /dev/null
+++ b/InstantAppTest/feature2/src/main/res/values/strings.xml
@@ -0,0 +1,3 @@
+<resources>
+
+</resources>
diff --git a/MaterialTest/app/src/test/java/com/example/jyheo/materialtest/ExampleUnitTest.java b/InstantAppTest/feature2/src/test/java/com/example/instantapptest/ExampleUnitTest.java
similarity index 50%
rename from MaterialTest/app/src/test/java/com/example/jyheo/materialtest/ExampleUnitTest.java
rename to InstantAppTest/feature2/src/test/java/com/example/instantapptest/ExampleUnitTest.java
index 09f1c37..7e20afa 100644
--- a/MaterialTest/app/src/test/java/com/example/jyheo/materialtest/ExampleUnitTest.java
+++ b/InstantAppTest/feature2/src/test/java/com/example/instantapptest/ExampleUnitTest.java
@@ -1,11 +1,13 @@
-package com.example.jyheo.materialtest;
+package com.example.instantapptest;
 
 import org.junit.Test;
 
 import static org.junit.Assert.*;
 
 /**
- * To work on unit tests, switch the Test Artifact in the Build Variants view.
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
  */
 public class ExampleUnitTest {
     @Test
diff --git a/LocationAware/gradle.properties b/InstantAppTest/gradle.properties
similarity index 78%
rename from LocationAware/gradle.properties
rename to InstantAppTest/gradle.properties
index 1d3591c..aac7c9b 100644
--- a/LocationAware/gradle.properties
+++ b/InstantAppTest/gradle.properties
@@ -9,10 +9,9 @@
 
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-# Default value: -Xmx10248m -XX:MaxPermSize=256m
-# org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
+org.gradle.jvmargs=-Xmx1536m
 
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
\ No newline at end of file
+# org.gradle.parallel=true
diff --git a/LocationAware/gradle/wrapper/gradle-wrapper.jar b/InstantAppTest/gradle/wrapper/gradle-wrapper.jar
similarity index 100%
rename from LocationAware/gradle/wrapper/gradle-wrapper.jar
rename to InstantAppTest/gradle/wrapper/gradle-wrapper.jar
diff --git a/MaterialTest/gradle/wrapper/gradle-wrapper.properties b/InstantAppTest/gradle/wrapper/gradle-wrapper.properties
similarity index 56%
rename from MaterialTest/gradle/wrapper/gradle-wrapper.properties
rename to InstantAppTest/gradle/wrapper/gradle-wrapper.properties
index 9a11f79..1e94d8b 100644
--- a/MaterialTest/gradle/wrapper/gradle-wrapper.properties
+++ b/InstantAppTest/gradle/wrapper/gradle-wrapper.properties
@@ -1,10 +1,6 @@
-<<<<<<< HEAD
-#Fri Sep 22 06:56:42 KST 2017
-=======
-#Tue Sep 12 18:37:05 KST 2017
->>>>>>> 5932659b29ea23ed218f881b7779a18d32db802a
+#Sat Nov 18 20:01:44 KST 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
diff --git a/LocationAware/gradlew b/InstantAppTest/gradlew
similarity index 100%
rename from LocationAware/gradlew
rename to InstantAppTest/gradlew
diff --git a/LocationAware/gradlew.bat b/InstantAppTest/gradlew.bat
similarity index 100%
rename from LocationAware/gradlew.bat
rename to InstantAppTest/gradlew.bat
diff --git a/InstantAppTest/instantapp/.gitignore b/InstantAppTest/instantapp/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/InstantAppTest/instantapp/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/InstantAppTest/instantapp/build.gradle b/InstantAppTest/instantapp/build.gradle
new file mode 100644
index 0000000..a771638
--- /dev/null
+++ b/InstantAppTest/instantapp/build.gradle
@@ -0,0 +1,7 @@
+apply plugin: 'com.android.instantapp'
+
+dependencies {
+    implementation project(':feature')
+    implementation project(':feature2')
+    implementation project(':base')
+}
diff --git a/InstantAppTest/settings.gradle b/InstantAppTest/settings.gradle
new file mode 100644
index 0000000..ace96be
--- /dev/null
+++ b/InstantAppTest/settings.gradle
@@ -0,0 +1 @@
+include ':feature', ':app', ':base', ':instantapp', ':feature2'
\ No newline at end of file
diff --git a/LocationAware/app/build.gradle b/LocationAware/app/build.gradle
deleted file mode 100644
index 886dabe..0000000
--- a/LocationAware/app/build.gradle
+++ /dev/null
@@ -1,27 +0,0 @@
-apply plugin: 'com.android.application'
-
-android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.3"
-
-    defaultConfig {
-        applicationId "com.example.jyheo.locationaware"
-        minSdkVersion 22
-        targetSdkVersion 25
-        versionCode 1
-        versionName "1.0"
-    }
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
-        }
-    }
-}
-
-dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    testCompile 'junit:junit:4.12'
-    compile 'com.android.support:appcompat-v7:25.3.1'
-    compile 'pub.devrel:easypermissions:0.4.3'
-}
diff --git a/LocationAware/app/proguard-rules.pro b/LocationAware/app/proguard-rules.pro
deleted file mode 100644
index 8a2f402..0000000
--- a/LocationAware/app/proguard-rules.pro
+++ /dev/null
@@ -1,17 +0,0 @@
-# Add project specific ProGuard rules here.
-# By default, the flags in this file are appended to flags specified
-# in C:\Android\sdk/tools/proguard/proguard-android.txt
-# You can edit the include path and order by changing the proguardFiles
-# directive in build.gradle.
-#
-# For more details, see
-#   http://developer.android.com/guide/developing/tools/proguard.html
-
-# Add any project specific keep options here:
-
-# If your project uses WebView with JS, uncomment the following
-# and specify the fully qualified class name to the JavaScript interface
-# class:
-#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
-#   public *;
-#}
diff --git a/LocationAware/app/src/androidTest/java/com/example/jyheo/locationaware/ApplicationTest.java b/LocationAware/app/src/androidTest/java/com/example/jyheo/locationaware/ApplicationTest.java
deleted file mode 100644
index 509f378..0000000
--- a/LocationAware/app/src/androidTest/java/com/example/jyheo/locationaware/ApplicationTest.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package com.example.jyheo.locationaware;
-
-import android.app.Application;
-import android.test.ApplicationTestCase;
-
-/**
- * <a href="http://d.android.com/tools/testing/testing_android.html">Testing Fundamentals</a>
- */
-public class ApplicationTest extends ApplicationTestCase<Application> {
-    public ApplicationTest() {
-        super(Application.class);
-    }
-}
\ No newline at end of file
diff --git a/LocationAware/app/src/main/res/mipmap-hdpi/ic_launcher.png b/LocationAware/app/src/main/res/mipmap-hdpi/ic_launcher.png
deleted file mode 100644
index cde69bc..0000000
Binary files a/LocationAware/app/src/main/res/mipmap-hdpi/ic_launcher.png and /dev/null differ
diff --git a/LocationAware/app/src/main/res/mipmap-mdpi/ic_launcher.png b/LocationAware/app/src/main/res/mipmap-mdpi/ic_launcher.png
deleted file mode 100644
index c133a0c..0000000
Binary files a/LocationAware/app/src/main/res/mipmap-mdpi/ic_launcher.png and /dev/null differ
diff --git a/LocationAware/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/LocationAware/app/src/main/res/mipmap-xhdpi/ic_launcher.png
deleted file mode 100644
index bfa42f0..0000000
Binary files a/LocationAware/app/src/main/res/mipmap-xhdpi/ic_launcher.png and /dev/null differ
diff --git a/LocationAware/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/LocationAware/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
deleted file mode 100644
index 324e72c..0000000
Binary files a/LocationAware/app/src/main/res/mipmap-xxhdpi/ic_launcher.png and /dev/null differ
diff --git a/LocationAware/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/LocationAware/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
deleted file mode 100644
index aee44e1..0000000
Binary files a/LocationAware/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png and /dev/null differ
diff --git a/LocationAware/app/src/main/res/values-w820dp/dimens.xml b/LocationAware/app/src/main/res/values-w820dp/dimens.xml
deleted file mode 100644
index 63fc816..0000000
--- a/LocationAware/app/src/main/res/values-w820dp/dimens.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<resources>
-    <!-- Example customization of dimensions originally defined in res/values/dimens.xml
-         (such as screen margins) for screens with more than 820dp of available width. This
-         would include 7" and 10" devices in landscape (~960dp and ~1280dp respectively). -->
-    <dimen name="activity_horizontal_margin">64dp</dimen>
-</resources>
diff --git a/LocationAware/app/src/main/res/values/dimens.xml b/LocationAware/app/src/main/res/values/dimens.xml
deleted file mode 100644
index 47c8224..0000000
--- a/LocationAware/app/src/main/res/values/dimens.xml
+++ /dev/null
@@ -1,5 +0,0 @@
-<resources>
-    <!-- Default screen margins, per the Android Design guidelines. -->
-    <dimen name="activity_horizontal_margin">16dp</dimen>
-    <dimen name="activity_vertical_margin">16dp</dimen>
-</resources>
diff --git a/MaterialTest/.idea/misc.xml b/MaterialTest/.idea/misc.xml
deleted file mode 100644
index 9adc8c9..0000000
--- a/MaterialTest/.idea/misc.xml
+++ /dev/null
@@ -1,62 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
-  </component>
-  <component name="NullableNotNullManager">
-    <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
-    <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
-    <option name="myNullables">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
-        </list>
-      </value>
-    </option>
-    <option name="myNotNulls">
-      <value>
-        <list size="4">
-          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
-          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
-        </list>
-      </value>
-    </option>
-  </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
-    <output url="file://$PROJECT_DIR$/build/classes" />
-  </component>
-  <component name="ProjectType">
-    <option name="id" value="Android" />
-  </component>
-  <component name="masterDetails">
-    <states>
-      <state key="ProjectJDKs.UI">
-        <settings>
-          <last-edited>Android API 24 Platform</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-    </states>
-  </component>
-</project>
\ No newline at end of file
diff --git a/MaterialTest/.idea/modules.xml b/MaterialTest/.idea/modules.xml
deleted file mode 100644
index 9649ca8..0000000
--- a/MaterialTest/.idea/modules.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ProjectModuleManager">
-    <modules>
-      <module fileurl="file://$PROJECT_DIR$/MaterialTest.iml" filepath="$PROJECT_DIR$/MaterialTest.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
-    </modules>
-  </component>
-</project>
\ No newline at end of file
diff --git a/MaterialTest/app/build.gradle b/MaterialTest/app/build.gradle
deleted file mode 100644
index 211f5a7..0000000
--- a/MaterialTest/app/build.gradle
+++ /dev/null
@@ -1,28 +0,0 @@
-apply plugin: 'com.android.application'
-
-android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.3"
-
-    defaultConfig {
-        applicationId "com.example.jyheo.materialtest"
-        minSdkVersion 22
-        targetSdkVersion 25
-        versionCode 1
-        versionName "1.0"
-    }
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
-        }
-    }
-}
-
-dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    testCompile 'junit:junit:4.12'
-    compile 'com.android.support:appcompat-v7:25.3.1'
-    compile 'com.android.support:cardview-v7:25.3.1'
-    compile 'com.android.support:recyclerview-v7:25.3.1'
-}
diff --git a/MaterialTest/app/google-services.json b/MaterialTest/app/google-services.json
deleted file mode 100644
index ac4a58e..0000000
--- a/MaterialTest/app/google-services.json
+++ /dev/null
@@ -1,55 +0,0 @@
-{
-  "project_info": {
-    "project_number": "874404589186",
-    "firebase_url": "https://materialtest-3165a.firebaseio.com",
-    "project_id": "materialtest-3165a",
-    "storage_bucket": "materialtest-3165a.appspot.com"
-  },
-  "client": [
-    {
-      "client_info": {
-        "mobilesdk_app_id": "1:874404589186:android:37f6758b7010d320",
-        "android_client_info": {
-          "package_name": "com.example.jyheo.materialtest"
-        }
-      },
-      "oauth_client": [
-        {
-          "client_id": "874404589186-it19e9cvmh2mmlabgkjrm2ul7sb37jqh.apps.googleusercontent.com",
-          "client_type": 1,
-          "android_info": {
-            "package_name": "com.example.jyheo.materialtest",
-            "certificate_hash": "7DE57CAA54CC70DA2D38BC6D451BFBE6FDEFD0A9"
-          }
-        },
-        {
-          "client_id": "874404589186-66eft9qq04km51ig1ehete04tspgrmo5.apps.googleusercontent.com",
-          "client_type": 3
-        }
-      ],
-      "api_key": [
-        {
-          "current_key": "AIzaSyAsyNNyPGfHTsT1kFp6fLtyGT8SqQhIhVM"
-        }
-      ],
-      "services": {
-        "analytics_service": {
-          "status": 1
-        },
-        "appinvite_service": {
-          "status": 2,
-          "other_platform_oauth_client": [
-            {
-              "client_id": "874404589186-66eft9qq04km51ig1ehete04tspgrmo5.apps.googleusercontent.com",
-              "client_type": 3
-            }
-          ]
-        },
-        "ads_service": {
-          "status": 2
-        }
-      }
-    }
-  ],
-  "configuration_version": "1"
-}
\ No newline at end of file
diff --git a/MaterialTest/app/proguard-rules.pro b/MaterialTest/app/proguard-rules.pro
deleted file mode 100644
index 8a2f402..0000000
--- a/MaterialTest/app/proguard-rules.pro
+++ /dev/null
@@ -1,17 +0,0 @@
-# Add project specific ProGuard rules here.
-# By default, the flags in this file are appended to flags specified
-# in C:\Android\sdk/tools/proguard/proguard-android.txt
-# You can edit the include path and order by changing the proguardFiles
-# directive in build.gradle.
-#
-# For more details, see
-#   http://developer.android.com/guide/developing/tools/proguard.html
-
-# Add any project specific keep options here:
-
-# If your project uses WebView with JS, uncomment the following
-# and specify the fully qualified class name to the JavaScript interface
-# class:
-#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
-#   public *;
-#}
diff --git a/MaterialTest/app/src/androidTest/java/com/example/jyheo/materialtest/ApplicationTest.java b/MaterialTest/app/src/androidTest/java/com/example/jyheo/materialtest/ApplicationTest.java
deleted file mode 100644
index 9393708..0000000
--- a/MaterialTest/app/src/androidTest/java/com/example/jyheo/materialtest/ApplicationTest.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package com.example.jyheo.materialtest;
-
-import android.app.Application;
-import android.test.ApplicationTestCase;
-
-/**
- * <a href="http://d.android.com/tools/testing/testing_android.html">Testing Fundamentals</a>
- */
-public class ApplicationTest extends ApplicationTestCase<Application> {
-    public ApplicationTest() {
-        super(Application.class);
-    }
-}
\ No newline at end of file
diff --git a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/Contact.java b/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/Contact.java
deleted file mode 100644
index 7c4772e..0000000
--- a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/Contact.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package com.example.jyheo.materialtest;
-
-import java.util.ArrayList;
-
-/**
- * Created by jyheo on 2016-07-22.
- * source: https://guides.codepath.com/android/using-the-recyclerview
- */
-
-public class Contact {
-    private String mName;
-    private boolean mOnline;
-
-    public Contact(String name, boolean online) {
-        mName = name;
-        mOnline = online;
-    }
-
-    public String getName() {
-        return mName;
-    }
-
-    public boolean isOnline() {
-        return mOnline;
-    }
-
-    private static int lastContactId = 0;
-
-    public static ArrayList<Contact> createContactsList(int numContacts) {
-        ArrayList<Contact> contacts = new ArrayList<Contact>();
-
-        for (int i = 1; i <= numContacts; i++) {
-            contacts.add(new Contact("Person " + ++lastContactId, i <= numContacts / 2));
-        }
-
-        return contacts;
-    }
-}
diff --git a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/ContactsAdapter.java b/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/ContactsAdapter.java
deleted file mode 100644
index 8d161af..0000000
--- a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/ContactsAdapter.java
+++ /dev/null
@@ -1,114 +0,0 @@
-package com.example.jyheo.materialtest;
-
-import android.content.Context;
-import android.support.v7.widget.RecyclerView;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.Button;
-import android.widget.TextView;
-import android.widget.Toast;
-
-import java.util.List;
-
-/**
- * Created by jyheo on 2016-07-22.
- * source: https://guides.codepath.com/android/using-the-recyclerview
- */
-// Create the basic adapter extending from RecyclerView.Adapter
-// Note that we specify the custom ViewHolder which gives us access to our views
-public class ContactsAdapter extends RecyclerView.Adapter<ContactsAdapter.ViewHolder> {
-
-    // Provide a direct reference to each of the views within a data item
-    // Used to cache the views within the item layout for fast access
-    public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
-        // Your holder should contain a member variable
-        // for any view that will be set as you render a row
-        public TextView nameTextView;
-        public Button messageButton;
-        private ContactsAdapter mContacts;
-
-        private Context context;
-
-        // We also create a constructor that accepts the entire item row
-        // and does the view lookups to find each subview
-        public ViewHolder(Context context, View itemView, ContactsAdapter contacts) {
-            // Stores the itemView in a public final member variable that can be used
-            // to access the context from any ViewHolder instance.
-            super(itemView);
-
-            nameTextView = (TextView) itemView.findViewById(R.id.contact_name);
-            messageButton = (Button) itemView.findViewById(R.id.message_button);
-
-            this.context = context;
-            this.mContacts = contacts;
-
-            messageButton.setOnClickListener(this);
-        }
-
-        @Override
-        public void onClick(View view) {
-            int position = getLayoutPosition(); // gets item position
-            // We can access the data within the views
-            Toast.makeText(context, nameTextView.getText() + Integer.toString(position), Toast.LENGTH_SHORT).show();
-            mContacts.removeItem(position);
-
-        }
-    }
-
-    // Store a member variable for the contacts
-    private List<Contact> mContacts;
-    // Store the context for easy access
-    private Context mContext;
-
-    // Pass in the contact array into the constructor
-    public ContactsAdapter(Context context, List<Contact> contacts) {
-        mContacts = contacts;
-        mContext = context;
-    }
-
-    // Easy access to the context object in the recyclerview
-    private Context getContext() {
-        return mContext;
-    }
-
-    // Usually involves inflating a layout from XML and returning the holder
-    @Override
-    public ContactsAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
-        Context context = parent.getContext();
-        LayoutInflater inflater = LayoutInflater.from(context);
-
-        // Inflate the custom layout
-        View contactView = inflater.inflate(R.layout.item_contact, parent, false);
-
-        // Return a new holder instance
-        ViewHolder viewHolder = new ViewHolder(context, contactView, this);
-        return viewHolder;
-    }
-
-    // Involves populating data into the item through holder
-    @Override
-    public void onBindViewHolder(ContactsAdapter.ViewHolder viewHolder, int position) {
-        // Get the data model based on position
-        Contact contact = mContacts.get(position);
-
-        // Set item views based on your views and data model
-        TextView textView = viewHolder.nameTextView;
-        textView.setText(contact.getName());
-        Button button = viewHolder.messageButton;
-        button.setText("Delete");
-    }
-
-    // Returns the total count of items in the list
-    @Override
-    public int getItemCount() {
-        return mContacts.size();
-    }
-
-    public void removeItem(int p) {
-        mContacts.remove(p);
-        notifyItemRemoved(p);
-
-    }
-
-}
diff --git a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/MainActivity.java b/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/MainActivity.java
deleted file mode 100644
index 5409c71..0000000
--- a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/MainActivity.java
+++ /dev/null
@@ -1,57 +0,0 @@
-package com.example.jyheo.materialtest;
-
-import android.support.v7.app.AppCompatActivity;
-import android.os.Bundle;
-import android.support.v7.widget.LinearLayoutManager;
-import android.support.v7.widget.RecyclerView;
-import android.support.v7.widget.StaggeredGridLayoutManager;
-import android.view.Menu;
-import android.view.MotionEvent;
-
-import java.util.ArrayList;
-
-public class MainActivity extends AppCompatActivity {
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
-
-        RecyclerView rvContacts = (RecyclerView) findViewById(R.id.rvContacts);
-
-        // Initialize contacts
-        contacts = Contact.createContactsList(20);
-        // Create adapter passing in the sample user data
-        ContactsAdapter adapter = new ContactsAdapter(this, contacts);
-        // Attach the adapter to the recyclerview to populate items
-        rvContacts.setAdapter(adapter);
-        // Set layout manager to position the items
-        //rvContacts.setLayoutManager(new LinearLayoutManager(this));
-
-        StaggeredGridLayoutManager gridLayoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
-        rvContacts.setLayoutManager(gridLayoutManager);
-
-        RecyclerView.ItemDecoration itemDecoration = new
-                MarginItemDecoration(20);
-        rvContacts.addItemDecoration(itemDecoration);
-
-        // optimizations if all item views are of the same height and width for significantly smoother scrolling:
-        rvContacts.setHasFixedSize(true);
-
-        // Add a new contact
-        contacts.add(0, new Contact("Barney", true));
-        // Notify the adapter that an item was inserted at position 0
-        adapter.notifyItemInserted(0);
-    }
-
-    ArrayList<Contact> contacts;
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        getMenuInflater().inflate(R.menu.main, menu);
-        return super.onCreateOptionsMenu(menu);
-
-    }
-}
-
-
diff --git a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/MarginItemDecoration.java b/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/MarginItemDecoration.java
deleted file mode 100644
index ed387c2..0000000
--- a/MaterialTest/app/src/main/java/com/example/jyheo/materialtest/MarginItemDecoration.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package com.example.jyheo.materialtest;
-
-import android.graphics.Rect;
-import android.support.v7.widget.RecyclerView;
-import android.view.View;
-
-/**
- * Created by jyheo on 2016-07-22.
- */
-public class MarginItemDecoration extends RecyclerView.ItemDecoration {
-
-    private final int mVerticalSpaceHeight;
-
-    public MarginItemDecoration(int mMarginSize) {
-        this.mVerticalSpaceHeight = mMarginSize;
-    }
-
-    @Override
-    public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
-                               RecyclerView.State state) {
-        outRect.bottom = mVerticalSpaceHeight;
-        outRect.right = mVerticalSpaceHeight;
-        outRect.left = mVerticalSpaceHeight;
-        outRect.top = mVerticalSpaceHeight;
-    }
-}
diff --git a/MaterialTest/app/src/main/res/layout/activity_main.xml b/MaterialTest/app/src/main/res/layout/activity_main.xml
deleted file mode 100644
index 2657638..0000000
--- a/MaterialTest/app/src/main/res/layout/activity_main.xml
+++ /dev/null
@@ -1,22 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:paddingBottom="@dimen/activity_vertical_margin"
-    android:paddingLeft="@dimen/activity_horizontal_margin"
-    android:paddingRight="@dimen/activity_horizontal_margin"
-    android:paddingTop="@dimen/activity_vertical_margin"
-    android:orientation="vertical"
-    tools:context="com.example.jyheo.materialtest.MainActivity">
-
-    <android.support.v7.widget.RecyclerView
-        android:id="@+id/rvContacts"
-        android:scrollbars="vertical"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:layout_marginTop="20dp"/>
-
-</LinearLayout>
diff --git a/MaterialTest/app/src/main/res/layout/item_contact.xml b/MaterialTest/app/src/main/res/layout/item_contact.xml
deleted file mode 100644
index ffe567c..0000000
--- a/MaterialTest/app/src/main/res/layout/item_contact.xml
+++ /dev/null
@@ -1,35 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<android.support.v7.widget.CardView
-    xmlns:card_view="http://schemas.android.com/apk/res-auto"
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    card_view:cardCornerRadius="8dp"
-    card_view:cardElevation="8dp">
-
-<LinearLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:orientation="vertical"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    android:paddingTop="10dp"
-    android:paddingBottom="10dp"
-    >
-
-    <TextView
-        android:id="@+id/contact_name"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_weight="1"
-        />
-
-    <Button
-        android:id="@+id/message_button"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:paddingLeft="16dp"
-        android:paddingRight="16dp"
-        android:textSize="10sp"
-        />
-</LinearLayout>
-</android.support.v7.widget.CardView>
\ No newline at end of file
diff --git a/MaterialTest/app/src/main/res/menu/main.xml b/MaterialTest/app/src/main/res/menu/main.xml
deleted file mode 100644
index 3c72e00..0000000
--- a/MaterialTest/app/src/main/res/menu/main.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<menu xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:android="http://schemas.android.com/apk/res/android">
-
-    <item android:title="Item"
-        android:id="@+id/addItem"
-        android:icon="@android:drawable/ic_input_add"
-        app:showAsAction="ifRoom"
-        android:visible="true"
-        android:enabled="true" />
-</menu>
\ No newline at end of file
diff --git a/MaterialTest/app/src/main/res/mipmap-hdpi/ic_launcher.png b/MaterialTest/app/src/main/res/mipmap-hdpi/ic_launcher.png
deleted file mode 100644
index cde69bc..0000000
Binary files a/MaterialTest/app/src/main/res/mipmap-hdpi/ic_launcher.png and /dev/null differ
diff --git a/MaterialTest/app/src/main/res/mipmap-mdpi/ic_launcher.png b/MaterialTest/app/src/main/res/mipmap-mdpi/ic_launcher.png
deleted file mode 100644
index c133a0c..0000000
Binary files a/MaterialTest/app/src/main/res/mipmap-mdpi/ic_launcher.png and /dev/null differ
diff --git a/MaterialTest/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/MaterialTest/app/src/main/res/mipmap-xhdpi/ic_launcher.png
deleted file mode 100644
index bfa42f0..0000000
Binary files a/MaterialTest/app/src/main/res/mipmap-xhdpi/ic_launcher.png and /dev/null differ
diff --git a/MaterialTest/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/MaterialTest/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
deleted file mode 100644
index 324e72c..0000000
Binary files a/MaterialTest/app/src/main/res/mipmap-xxhdpi/ic_launcher.png and /dev/null differ
diff --git a/MaterialTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/MaterialTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
deleted file mode 100644
index aee44e1..0000000
Binary files a/MaterialTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png and /dev/null differ
diff --git a/MaterialTest/app/src/main/res/values-w820dp/dimens.xml b/MaterialTest/app/src/main/res/values-w820dp/dimens.xml
deleted file mode 100644
index 63fc816..0000000
--- a/MaterialTest/app/src/main/res/values-w820dp/dimens.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<resources>
-    <!-- Example customization of dimensions originally defined in res/values/dimens.xml
-         (such as screen margins) for screens with more than 820dp of available width. This
-         would include 7" and 10" devices in landscape (~960dp and ~1280dp respectively). -->
-    <dimen name="activity_horizontal_margin">64dp</dimen>
-</resources>
diff --git a/MaterialTest/app/src/main/res/values/dimens.xml b/MaterialTest/app/src/main/res/values/dimens.xml
deleted file mode 100644
index 47c8224..0000000
--- a/MaterialTest/app/src/main/res/values/dimens.xml
+++ /dev/null
@@ -1,5 +0,0 @@
-<resources>
-    <!-- Default screen margins, per the Android Design guidelines. -->
-    <dimen name="activity_horizontal_margin">16dp</dimen>
-    <dimen name="activity_vertical_margin">16dp</dimen>
-</resources>
diff --git a/MaterialTest/app/src/main/res/values/strings.xml b/MaterialTest/app/src/main/res/values/strings.xml
deleted file mode 100644
index 24721ef..0000000
--- a/MaterialTest/app/src/main/res/values/strings.xml
+++ /dev/null
@@ -1,3 +0,0 @@
-<resources>
-    <string name="app_name">MaterialTest</string>
-</resources>
diff --git a/MaterialTest/settings.gradle b/MaterialTest/settings.gradle
deleted file mode 100644
index e7b4def..0000000
--- a/MaterialTest/settings.gradle
+++ /dev/null
@@ -1 +0,0 @@
-include ':app'
diff --git a/Notification/app/build.gradle b/Notification/app/build.gradle
index 049b436..57c91b7 100644
--- a/Notification/app/build.gradle
+++ b/Notification/app/build.gradle
@@ -1,27 +1,34 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.3"
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
 
     defaultConfig {
-        applicationId "com.example.jyheo.notification"
-        minSdkVersion 22
-        targetSdkVersion 25
+        applicationId "com.example.myapplication"
+        minSdkVersion 23
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
+
     buildTypes {
         release {
             minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
+
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    compile 'com.android.support:appcompat-v7:25.3.1'
-    compile 'com.android.support.constraint:constraint-layout:1.0.2'
-    testCompile 'junit:junit:4.12'
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
 }
diff --git a/Notification/app/src/main/java/com/example/jyheo/notification/MainActivity.java b/Notification/app/src/main/java/com/example/jyheo/notification/MainActivity.java
index 1b2cf8a..9254f0f 100644
--- a/Notification/app/src/main/java/com/example/jyheo/notification/MainActivity.java
+++ b/Notification/app/src/main/java/com/example/jyheo/notification/MainActivity.java
@@ -1,43 +1,58 @@
 package com.example.jyheo.notification;
 
+import android.app.NotificationChannel;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.app.TaskStackBuilder;
-import android.content.Context;
 import android.content.Intent;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.net.Uri;
-import android.support.v7.app.AppCompatActivity;
+import android.os.Build;
 import android.os.Bundle;
-import android.support.v7.app.NotificationCompat;
 import android.util.Log;
 import android.view.View;
 
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.NotificationManagerCompat;
+
 public class MainActivity extends AppCompatActivity {
 
     public final static int MY_NOTIFICATION_ID = 1;
+    final private String CHANNEL_ID = "default";
+    private NotificationManagerCompat mNotificationManagerCompat;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+
+        mNotificationManagerCompat = NotificationManagerCompat.from(this);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { // API 26
+            mNotificationManagerCompat.createNotificationChannel(
+                    new NotificationChannel(CHANNEL_ID, "default channel",
+                            NotificationManager.IMPORTANCE_DEFAULT));
+        }
     }
 
     public void onSimpleNotification(View v) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this);
+        if (!mNotificationManagerCompat.areNotificationsEnabled())
+            return;
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID);
         mBuilder.setSmallIcon(R.drawable.ic_alarm_on_black_24dp);
         mBuilder.setContentTitle(getResources().getString(R.string.notif_title));
         mBuilder.setContentText(getResources().getString(R.string.notif_body));
 
-        NotificationManager mNotificationManager =
-                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
         // MY_NOTIFICATION_ID allows you to update the notification later on.
-        mNotificationManager.notify(MY_NOTIFICATION_ID, mBuilder.build());
+        mNotificationManagerCompat.notify(MY_NOTIFICATION_ID, mBuilder.build());
     }
 
     public void onActionNotificationSpecial(View v) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this);
+        if (!mNotificationManagerCompat.areNotificationsEnabled())
+            return;
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID);
         mBuilder.setSmallIcon(R.drawable.ic_alarm_on_black_24dp);
         mBuilder.setContentTitle(getResources().getString(R.string.notif_title));
         mBuilder.setContentText(getResources().getString(R.string.notif_body));
@@ -50,12 +65,13 @@ public void onActionNotificationSpecial(View v) {
         mBuilder.setContentIntent(pIntent);
         mBuilder.setAutoCancel(true);
 
-        ((NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE))
-                .notify(MY_NOTIFICATION_ID, mBuilder.build());
+        mNotificationManagerCompat.notify(MY_NOTIFICATION_ID, mBuilder.build());
     }
 
     public void onActionNotificationRegular(View v) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this);
+        if (!mNotificationManagerCompat.areNotificationsEnabled())
+            return;
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID);
         mBuilder.setSmallIcon(R.drawable.ic_alarm_on_black_24dp);
         mBuilder.setContentTitle(getResources().getString(R.string.notif_title));
         mBuilder.setContentText(getResources().getString(R.string.notif_body));
@@ -71,12 +87,13 @@ public void onActionNotificationRegular(View v) {
         mBuilder.setContentIntent(pIntent);
         mBuilder.setAutoCancel(true);
 
-        ((NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE))
-                .notify(MY_NOTIFICATION_ID, mBuilder.build());
+        mNotificationManagerCompat.notify(MY_NOTIFICATION_ID, mBuilder.build());
     }
 
     public void onActionButtonNotification(View v) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this);
+        if (!mNotificationManagerCompat.areNotificationsEnabled())
+            return;
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID);
         mBuilder.setSmallIcon(R.drawable.ic_alarm_on_black_24dp);
         mBuilder.setContentTitle(getResources().getString(R.string.notif_title));
         mBuilder.setContentText(getResources().getString(R.string.notif_body));
@@ -87,13 +104,13 @@ public void onActionButtonNotification(View v) {
                 0, callintent, PendingIntent.FLAG_CANCEL_CURRENT);
         mBuilder.addAction(R.drawable.ic_phone_black_24dp, "Call", pIntent);
 
-        NotificationManager mNotificationManager =
-                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
-        mNotificationManager.notify(MY_NOTIFICATION_ID, mBuilder.build());
+        mNotificationManagerCompat.notify(MY_NOTIFICATION_ID, mBuilder.build());
     }
 
     public void onExpandableNotification(View v) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this);
+        if (!mNotificationManagerCompat.areNotificationsEnabled())
+            return;
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID);
         mBuilder.setSmallIcon(R.drawable.ic_alarm_on_black_24dp);
         mBuilder.setContentTitle(getResources().getString(R.string.notif_title));
         mBuilder.setContentText(getResources().getString(R.string.notif_body));
@@ -109,20 +126,18 @@ public void onExpandableNotification(View v) {
                 new NotificationCompat.BigPictureStyle().bigPicture(largeIcon);
         mBuilder.setStyle(bpStyle);
 
-        NotificationManager mNotificationManager =
-                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
-        mNotificationManager.notify(MY_NOTIFICATION_ID, mBuilder.build());
+        mNotificationManagerCompat.notify(MY_NOTIFICATION_ID, mBuilder.build());
     }
 
     public void onProgressNotification(View v) {
-        final NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this);
+        if (!mNotificationManagerCompat.areNotificationsEnabled())
+            return;
+        final NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID);
         mBuilder.setSmallIcon(R.drawable.ic_alarm_on_black_24dp);
         mBuilder.setContentTitle("Download");
         mBuilder.setContentText("Download in progress");
         mBuilder.setAutoCancel(true);
 
-        final NotificationManager mNotificationManager =
-                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
         new Thread(
                 new Runnable() {
                     @Override
@@ -130,7 +145,7 @@ public void run() {
                         int incr;
                         for (incr = 0; incr <= 100; incr += 5) {
                             mBuilder.setProgress(100, incr, false);
-                            mNotificationManager.notify(MY_NOTIFICATION_ID, mBuilder.build());
+                            mNotificationManagerCompat.notify(MY_NOTIFICATION_ID, mBuilder.build());
                             try {
                                 Thread.sleep(5 * 1000); // Sleep for 5 seconds
                             } catch (InterruptedException e) {
@@ -139,7 +154,7 @@ public void run() {
                         }
                         mBuilder.setContentText("Download complete")
                                 .setProgress(0, 0, false); // Removes the progress bar
-                        mNotificationManager.notify(MY_NOTIFICATION_ID, mBuilder.build());
+                        mNotificationManagerCompat.notify(MY_NOTIFICATION_ID, mBuilder.build());
                     }
                 }
         ).start();
diff --git a/Notification/app/src/main/java/com/example/jyheo/notification/SecondActivity.java b/Notification/app/src/main/java/com/example/jyheo/notification/SecondActivity.java
index 671f21b..96a6de5 100644
--- a/Notification/app/src/main/java/com/example/jyheo/notification/SecondActivity.java
+++ b/Notification/app/src/main/java/com/example/jyheo/notification/SecondActivity.java
@@ -1,7 +1,7 @@
 package com.example.jyheo.notification;
 
-import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import androidx.appcompat.app.AppCompatActivity;
 
 public class SecondActivity extends AppCompatActivity {
 
diff --git a/Notification/app/src/main/java/com/example/jyheo/notification/TempActivity.java b/Notification/app/src/main/java/com/example/jyheo/notification/TempActivity.java
index f307b76..d4fd86c 100644
--- a/Notification/app/src/main/java/com/example/jyheo/notification/TempActivity.java
+++ b/Notification/app/src/main/java/com/example/jyheo/notification/TempActivity.java
@@ -1,7 +1,7 @@
 package com.example.jyheo.notification;
 
-import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import androidx.appcompat.app.AppCompatActivity;
 
 public class TempActivity extends AppCompatActivity {
 
diff --git a/Notification/build.gradle b/Notification/build.gradle
index c2eea8e..db1fb47 100644
--- a/Notification/build.gradle
+++ b/Notification/build.gradle
@@ -3,9 +3,10 @@
 buildscript {
     repositories {
         jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.6.2'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -15,6 +16,7 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
+        google()
     }
 }
 
diff --git a/Notification/gradle.properties b/Notification/gradle.properties
index 1d3591c..199d16e 100644
--- a/Notification/gradle.properties
+++ b/Notification/gradle.properties
@@ -1,18 +1,20 @@
 # Project-wide Gradle settings.
-
 # IDE (e.g. Android Studio) users:
 # Gradle settings configured through the IDE *will override*
 # any settings specified in this file.
-
 # For more details on how to configure your build environment visit
 # http://www.gradle.org/docs/current/userguide/build_environment.html
-
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-# Default value: -Xmx10248m -XX:MaxPermSize=256m
-# org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
-
+org.gradle.jvmargs=-Xmx1536m
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
\ No newline at end of file
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
+
diff --git a/Notification/gradle/wrapper/gradle-wrapper.jar b/Notification/gradle/wrapper/gradle-wrapper.jar
index 13372ae..f6b961f 100644
Binary files a/Notification/gradle/wrapper/gradle-wrapper.jar and b/Notification/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/Notification/gradle/wrapper/gradle-wrapper.properties b/Notification/gradle/wrapper/gradle-wrapper.properties
index fd3ec86..ac05ce9 100644
--- a/Notification/gradle/wrapper/gradle-wrapper.properties
+++ b/Notification/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Wed Sep 06 16:24:31 KST 2017
+#Tue Apr 14 22:44:46 KST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
diff --git a/Notification/gradlew b/Notification/gradlew
index 9d82f78..cccdd3d 100644
--- a/Notification/gradlew
+++ b/Notification/gradlew
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 ##############################################################################
 ##
@@ -6,20 +6,38 @@
 ##
 ##############################################################################
 
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
 
 APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
 
-warn ( ) {
+warn () {
     echo "$*"
 }
 
-die ( ) {
+die () {
     echo
     echo "$*"
     echo
@@ -30,6 +48,7 @@ die ( ) {
 cygwin=false
 msys=false
 darwin=false
+nonstop=false
 case "`uname`" in
   CYGWIN* )
     cygwin=true
@@ -40,26 +59,11 @@ case "`uname`" in
   MINGW* )
     msys=true
     ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
 esac
 
-# Attempt to set APP_HOME
-# Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
-done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
-
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
 # Determine the Java command to use to start the JVM.
@@ -85,7 +89,7 @@ location of your Java installation."
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
     MAX_FD_LIMIT=`ulimit -H -n`
     if [ $? -eq 0 ] ; then
         if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
@@ -150,11 +154,19 @@ if $cygwin ; then
     esac
 fi
 
-# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
-function splitJvmOpts() {
-    JVM_OPTS=("$@")
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
 }
-eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
-JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
 
-exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"
+exec "$JAVACMD" "$@"
diff --git a/Notification/gradlew.bat b/Notification/gradlew.bat
index 8a0b282..f955316 100644
--- a/Notification/gradlew.bat
+++ b/Notification/gradlew.bat
@@ -8,14 +8,14 @@
 @rem Set local scope for the variables with windows NT shell
 if "%OS%"=="Windows_NT" setlocal
 
-@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
-
 set DIRNAME=%~dp0
 if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
 
@@ -46,10 +46,9 @@ echo location of your Java installation.
 goto fail
 
 :init
-@rem Get command-line arguments, handling Windowz variants
+@rem Get command-line arguments, handling Windows variants
 
 if not "%OS%" == "Windows_NT" goto win9xME_args
-if "%@eval[2+2]" == "4" goto 4NT_args
 
 :win9xME_args
 @rem Slurp the command line arguments.
@@ -60,11 +59,6 @@ set _SKIP=2
 if "x%~1" == "x" goto execute
 
 set CMD_LINE_ARGS=%*
-goto execute
-
-:4NT_args
-@rem Get arguments from the 4NT Shell from JP Software
-set CMD_LINE_ARGS=%$
 
 :execute
 @rem Setup the command line
diff --git a/Preferences/.gitignore b/Preferences/.gitignore
new file mode 100644
index 0000000..603b140
--- /dev/null
+++ b/Preferences/.gitignore
@@ -0,0 +1,14 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
diff --git a/Preferences/app/.gitignore b/Preferences/app/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/Preferences/app/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/Preferences/app/build.gradle b/Preferences/app/build.gradle
new file mode 100644
index 0000000..5586a28
--- /dev/null
+++ b/Preferences/app/build.gradle
@@ -0,0 +1,41 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 29
+
+    defaultConfig {
+        applicationId "com.example.preferences"
+        minSdkVersion 23
+        targetSdkVersion 29
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+
+    buildFeatures {
+        viewBinding true
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    implementation 'androidx.preference:preference:1.1.0'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+
+}
\ No newline at end of file
diff --git a/Preferences/app/proguard-rules.pro b/Preferences/app/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/Preferences/app/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/Preferences/app/src/androidTest/java/com/example/preferences/ExampleInstrumentedTest.java b/Preferences/app/src/androidTest/java/com/example/preferences/ExampleInstrumentedTest.java
new file mode 100644
index 0000000..fd85831
--- /dev/null
+++ b/Preferences/app/src/androidTest/java/com/example/preferences/ExampleInstrumentedTest.java
@@ -0,0 +1,26 @@
+package com.example.preferences;
+
+import android.content.Context;
+
+import androidx.test.platform.app.InstrumentationRegistry;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        assertEquals("com.example.preferences", appContext.getPackageName());
+    }
+}
\ No newline at end of file
diff --git a/Preferences/app/src/main/AndroidManifest.xml b/Preferences/app/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..517ccc8
--- /dev/null
+++ b/Preferences/app/src/main/AndroidManifest.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.preferences">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <activity
+            android:name=".SettingsActivity"
+            android:label="@string/title_activity_settings"
+            android:parentActivityName=".MainActivity"></activity>
+        <activity android:name=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file
diff --git a/Preferences/app/src/main/java/com/example/preferences/MainActivity.java b/Preferences/app/src/main/java/com/example/preferences/MainActivity.java
new file mode 100644
index 0000000..8be3429
--- /dev/null
+++ b/Preferences/app/src/main/java/com/example/preferences/MainActivity.java
@@ -0,0 +1,63 @@
+package com.example.preferences;
+
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.preference.PreferenceManager;
+
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.os.Bundle;
+import android.provider.Settings;
+import android.view.View;
+
+import com.example.preferences.databinding.ActivityMainBinding;
+
+public class MainActivity extends AppCompatActivity {
+
+    private final String pref_name = "pref";
+    private final String pref_key_name = "name";
+    private final String pref_key_address = "address";
+    private final String pref_key_airplane = "airplane";
+    ActivityMainBinding binding;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+
+        SharedPreferences pref = getSharedPreferences(pref_name, MODE_PRIVATE);
+        binding.editName.setText(pref.getString(pref_key_name, ""));
+        binding.editAddress.setText(pref.getString(pref_key_address, ""));
+        binding.switchMode.setChecked(pref.getBoolean(pref_key_airplane, false));
+
+        /*binding.button.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                startActivity(new Intent(MainActivity.this, SettingsActivity.class));
+            }
+        });*/
+        binding.button.setOnClickListener(v -> startActivity(new Intent(this, SettingsActivity.class)));
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+
+        SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(this);
+        String str = "signature: " + pref.getString("signature", "") + "\n" +
+            "reply: " + pref.getString("reply", "") + "\n" +
+            "sync: " + pref.getBoolean("sync", false) + "\n" +
+            "attachment: " + pref.getBoolean("attachment", false);
+        binding.textSettings.setText(str);
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        SharedPreferences.Editor pref = getSharedPreferences(pref_name, MODE_PRIVATE).edit();
+        pref.putString(pref_key_name, binding.editName.getText().toString());
+        pref.putString(pref_key_address, binding.editAddress.getText().toString());
+        pref.putBoolean(pref_key_airplane, binding.switchMode.isChecked());
+        pref.apply();
+    }
+}
\ No newline at end of file
diff --git a/Preferences/app/src/main/java/com/example/preferences/SettingsActivity.java b/Preferences/app/src/main/java/com/example/preferences/SettingsActivity.java
new file mode 100644
index 0000000..990d773
--- /dev/null
+++ b/Preferences/app/src/main/java/com/example/preferences/SettingsActivity.java
@@ -0,0 +1,31 @@
+package com.example.preferences;
+
+import android.os.Bundle;
+
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.preference.PreferenceFragmentCompat;
+
+public class SettingsActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.settings_activity);
+        getSupportFragmentManager()
+                .beginTransaction()
+                .replace(R.id.settings, new SettingsFragment())
+                .commit();
+        ActionBar actionBar = getSupportActionBar();
+        if (actionBar != null) {
+            actionBar.setDisplayHomeAsUpEnabled(true);
+        }
+    }
+
+    public static class SettingsFragment extends PreferenceFragmentCompat {
+        @Override
+        public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+            setPreferencesFromResource(R.xml.root_preferences, rootKey);
+        }
+    }
+}
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/drawable-v24/ic_launcher_foreground.xml b/Preferences/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
new file mode 100644
index 0000000..2b068d1
--- /dev/null
+++ b/Preferences/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path android:pathData="M31,63.928c0,0 6.4,-11 12.1,-13.1c7.2,-2.6 26,-1.4 26,-1.4l38.1,38.1L107,108.928l-32,-1L31,63.928z">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="85.84757"
+                android:endY="92.4963"
+                android:startX="42.9492"
+                android:startY="49.59793"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M65.3,45.828l3.8,-6.6c0.2,-0.4 0.1,-0.9 -0.3,-1.1c-0.4,-0.2 -0.9,-0.1 -1.1,0.3l-3.9,6.7c-6.3,-2.8 -13.4,-2.8 -19.7,0l-3.9,-6.7c-0.2,-0.4 -0.7,-0.5 -1.1,-0.3C38.8,38.328 38.7,38.828 38.9,39.228l3.8,6.6C36.2,49.428 31.7,56.028 31,63.928h46C76.3,56.028 71.8,49.428 65.3,45.828zM43.4,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2c-0.3,-0.7 -0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C45.3,56.528 44.5,57.328 43.4,57.328L43.4,57.328zM64.6,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2s-0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C66.5,56.528 65.6,57.328 64.6,57.328L64.6,57.328z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/drawable/ic_baseline_mail_outline_24.xml b/Preferences/app/src/main/res/drawable/ic_baseline_mail_outline_24.xml
new file mode 100644
index 0000000..f108062
--- /dev/null
+++ b/Preferences/app/src/main/res/drawable/ic_baseline_mail_outline_24.xml
@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M20,4L4,4c-1.1,0 -1.99,0.9 -1.99,2L2,18c0,1.1 0.9,2 2,2h16c1.1,0 2,-0.9 2,-2L22,6c0,-1.1 -0.9,-2 -2,-2zM20,18L4,18L4,8l8,5 8,-5v10zM12,11L4,6h16l-8,5z"/>
+</vector>
diff --git a/Preferences/app/src/main/res/drawable/ic_baseline_sync_24.xml b/Preferences/app/src/main/res/drawable/ic_baseline_sync_24.xml
new file mode 100644
index 0000000..c2f773a
--- /dev/null
+++ b/Preferences/app/src/main/res/drawable/ic_baseline_sync_24.xml
@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M12,4L12,1L8,5l4,4L12,6c3.31,0 6,2.69 6,6 0,1.01 -0.25,1.97 -0.7,2.8l1.46,1.46C19.54,15.03 20,13.57 20,12c0,-4.42 -3.58,-8 -8,-8zM12,18c-3.31,0 -6,-2.69 -6,-6 0,-1.01 0.25,-1.97 0.7,-2.8L5.24,7.74C4.46,8.97 4,10.43 4,12c0,4.42 3.58,8 8,8v3l4,-4 -4,-4v3z"/>
+</vector>
diff --git a/Preferences/app/src/main/res/drawable/ic_launcher_background.xml b/Preferences/app/src/main/res/drawable/ic_launcher_background.xml
new file mode 100644
index 0000000..07d5da9
--- /dev/null
+++ b/Preferences/app/src/main/res/drawable/ic_launcher_background.xml
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#3DDC84"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+</vector>
diff --git a/Preferences/app/src/main/res/layout/activity_main.xml b/Preferences/app/src/main/res/layout/activity_main.xml
new file mode 100644
index 0000000..23100ef
--- /dev/null
+++ b/Preferences/app/src/main/res/layout/activity_main.xml
@@ -0,0 +1,76 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:padding="5dp"
+    tools:context=".MainActivity">
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Name:"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <EditText
+        android:id="@+id/editName"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:ems="10"
+        android:inputType="textPersonName"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textView" />
+
+    <Switch
+        android:id="@+id/switchMode"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:text="Air-plane Mode"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/editName" />
+
+    <TextView
+        android:id="@+id/textView3"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:text="Address"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/switchMode" />
+
+    <EditText
+        android:id="@+id/editAddress"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:ems="10"
+        android:inputType="textPersonName"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textView3" />
+
+    <Button
+        android:id="@+id/button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="16dp"
+        android:text="Settings Activity"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/editAddress" />
+
+    <TextView
+        android:id="@+id/textSettings"
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        android:layout_marginTop="8dp"
+        android:text="Settings"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/button" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/FragmentExample/app/src/main/res/layout/activity_details.xml b/Preferences/app/src/main/res/layout/settings_activity.xml
similarity index 57%
rename from FragmentExample/app/src/main/res/layout/activity_details.xml
rename to Preferences/app/src/main/res/layout/settings_activity.xml
index f6ef3a6..de6591a 100644
--- a/FragmentExample/app/src/main/res/layout/activity_details.xml
+++ b/Preferences/app/src/main/res/layout/settings_activity.xml
@@ -1,12 +1,9 @@
-<?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:orientation="vertical">
+    android:layout_height="match_parent">
 
     <FrameLayout
-        android:id="@+id/details"
+        android:id="@+id/settings"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />
-
-</LinearLayout>
+</LinearLayout>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml b/Preferences/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/Preferences/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml b/Preferences/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/Preferences/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/mipmap-hdpi/ic_launcher.png b/Preferences/app/src/main/res/mipmap-hdpi/ic_launcher.png
new file mode 100644
index 0000000..a571e60
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-hdpi/ic_launcher.png differ
diff --git a/Preferences/app/src/main/res/mipmap-hdpi/ic_launcher_round.png b/Preferences/app/src/main/res/mipmap-hdpi/ic_launcher_round.png
new file mode 100644
index 0000000..61da551
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-hdpi/ic_launcher_round.png differ
diff --git a/Preferences/app/src/main/res/mipmap-mdpi/ic_launcher.png b/Preferences/app/src/main/res/mipmap-mdpi/ic_launcher.png
new file mode 100644
index 0000000..c41dd28
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-mdpi/ic_launcher.png differ
diff --git a/Preferences/app/src/main/res/mipmap-mdpi/ic_launcher_round.png b/Preferences/app/src/main/res/mipmap-mdpi/ic_launcher_round.png
new file mode 100644
index 0000000..db5080a
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-mdpi/ic_launcher_round.png differ
diff --git a/Preferences/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/Preferences/app/src/main/res/mipmap-xhdpi/ic_launcher.png
new file mode 100644
index 0000000..6dba46d
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-xhdpi/ic_launcher.png differ
diff --git a/Preferences/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png b/Preferences/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..da31a87
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png differ
diff --git a/Preferences/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/Preferences/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
new file mode 100644
index 0000000..15ac681
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-xxhdpi/ic_launcher.png differ
diff --git a/Preferences/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png b/Preferences/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..b216f2d
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png differ
diff --git a/Preferences/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/Preferences/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
new file mode 100644
index 0000000..f25a419
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ
diff --git a/Preferences/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png b/Preferences/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..e96783c
Binary files /dev/null and b/Preferences/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png differ
diff --git a/Preferences/app/src/main/res/values/arrays.xml b/Preferences/app/src/main/res/values/arrays.xml
new file mode 100644
index 0000000..6cf9ed4
--- /dev/null
+++ b/Preferences/app/src/main/res/values/arrays.xml
@@ -0,0 +1,12 @@
+<resources>
+    <!-- Reply Preference -->
+    <string-array name="reply_entries">
+        <item>Reply</item>
+        <item>Reply to all</item>
+    </string-array>
+
+    <string-array name="reply_values">
+        <item>reply</item>
+        <item>reply_all</item>
+    </string-array>
+</resources>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/values/colors.xml b/Preferences/app/src/main/res/values/colors.xml
new file mode 100644
index 0000000..4faecfa
--- /dev/null
+++ b/Preferences/app/src/main/res/values/colors.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="colorPrimary">#6200EE</color>
+    <color name="colorPrimaryDark">#3700B3</color>
+    <color name="colorAccent">#03DAC5</color>
+</resources>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/values/strings.xml b/Preferences/app/src/main/res/values/strings.xml
new file mode 100644
index 0000000..49674d0
--- /dev/null
+++ b/Preferences/app/src/main/res/values/strings.xml
@@ -0,0 +1,19 @@
+<resources>
+    <string name="app_name">Preferences</string>
+    <string name="title_activity_settings">SettingsActivity</string>
+
+    <!-- Preference Titles -->
+    <string name="messages_header">Messages</string>
+    <string name="sync_header">Sync</string>
+
+    <!-- Messages Preferences -->
+    <string name="signature_title">Your signature</string>
+    <string name="reply_title">Default reply action</string>
+
+    <!-- Sync Preferences -->
+    <string name="sync_title">Sync email periodically</string>
+    <string name="attachment_title">Download incoming attachments</string>
+    <string name="attachment_summary_on">Automatically download attachments for incoming emails
+    </string>
+    <string name="attachment_summary_off">Only download attachments when manually requested</string>
+</resources>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/values/styles.xml b/Preferences/app/src/main/res/values/styles.xml
new file mode 100644
index 0000000..fac9291
--- /dev/null
+++ b/Preferences/app/src/main/res/values/styles.xml
@@ -0,0 +1,10 @@
+<resources>
+    <!-- Base application theme. -->
+    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+        <!-- Customize your theme here. -->
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+    </style>
+
+</resources>
\ No newline at end of file
diff --git a/Preferences/app/src/main/res/xml/root_preferences.xml b/Preferences/app/src/main/res/xml/root_preferences.xml
new file mode 100644
index 0000000..ef96322
--- /dev/null
+++ b/Preferences/app/src/main/res/xml/root_preferences.xml
@@ -0,0 +1,37 @@
+<PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <PreferenceCategory app:title="@string/messages_header"
+        app:icon="@drawable/ic_baseline_mail_outline_24">
+
+        <EditTextPreference
+            app:key="signature"
+            app:title="@string/signature_title"
+            app:useSimpleSummaryProvider="true" />
+
+        <ListPreference
+            app:defaultValue="reply"
+            app:entries="@array/reply_entries"
+            app:entryValues="@array/reply_values"
+            app:key="reply"
+            app:title="@string/reply_title"
+            app:useSimpleSummaryProvider="true" />
+
+    </PreferenceCategory>
+
+    <PreferenceCategory app:title="@string/sync_header"
+        app:icon="@drawable/ic_baseline_sync_24">
+
+        <SwitchPreferenceCompat
+            app:key="sync"
+            app:title="@string/sync_title" />
+
+        <SwitchPreferenceCompat
+            app:dependency="sync"
+            app:key="attachment"
+            app:summaryOff="@string/attachment_summary_off"
+            app:summaryOn="@string/attachment_summary_on"
+            app:title="@string/attachment_title" />
+
+    </PreferenceCategory>
+
+</PreferenceScreen>
\ No newline at end of file
diff --git a/Preferences/app/src/test/java/com/example/preferences/ExampleUnitTest.java b/Preferences/app/src/test/java/com/example/preferences/ExampleUnitTest.java
new file mode 100644
index 0000000..1055cf8
--- /dev/null
+++ b/Preferences/app/src/test/java/com/example/preferences/ExampleUnitTest.java
@@ -0,0 +1,17 @@
+package com.example.preferences;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+public class ExampleUnitTest {
+    @Test
+    public void addition_isCorrect() {
+        assertEquals(4, 2 + 2);
+    }
+}
\ No newline at end of file
diff --git a/LocationAware/build.gradle b/Preferences/build.gradle
similarity index 82%
rename from LocationAware/build.gradle
rename to Preferences/build.gradle
index c2eea8e..da807a2 100644
--- a/LocationAware/build.gradle
+++ b/Preferences/build.gradle
@@ -1,11 +1,11 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
-
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath "com.android.tools.build:gradle:4.0.0"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -14,10 +14,11 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
     }
 }
 
 task clean(type: Delete) {
     delete rootProject.buildDir
-}
+}
\ No newline at end of file
diff --git a/Preferences/gradle.properties b/Preferences/gradle.properties
new file mode 100644
index 0000000..c52ac9b
--- /dev/null
+++ b/Preferences/gradle.properties
@@ -0,0 +1,19 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx2048m
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app"s APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
\ No newline at end of file
diff --git a/Preferences/gradle/wrapper/gradle-wrapper.jar b/Preferences/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..f6b961f
Binary files /dev/null and b/Preferences/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/Preferences/gradle/wrapper/gradle-wrapper.properties b/Preferences/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..3a4578b
--- /dev/null
+++ b/Preferences/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Fri Jun 12 00:10:45 KST 2020
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
diff --git a/Preferences/gradlew b/Preferences/gradlew
new file mode 100644
index 0000000..cccdd3d
--- /dev/null
+++ b/Preferences/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/Preferences/gradlew.bat b/Preferences/gradlew.bat
new file mode 100644
index 0000000..f955316
--- /dev/null
+++ b/Preferences/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/Preferences/settings.gradle b/Preferences/settings.gradle
new file mode 100644
index 0000000..c3df3fe
--- /dev/null
+++ b/Preferences/settings.gradle
@@ -0,0 +1,2 @@
+include ':app'
+rootProject.name = "Preferences"
\ No newline at end of file
diff --git a/RecyclerView/.gitignore b/RecyclerView/.gitignore
new file mode 100644
index 0000000..603b140
--- /dev/null
+++ b/RecyclerView/.gitignore
@@ -0,0 +1,14 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
diff --git a/RecyclerView/app/.gitignore b/RecyclerView/app/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/RecyclerView/app/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/RecyclerView/app/build.gradle b/RecyclerView/app/build.gradle
new file mode 100644
index 0000000..d1db9ed
--- /dev/null
+++ b/RecyclerView/app/build.gradle
@@ -0,0 +1,38 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
+
+    defaultConfig {
+        applicationId "com.example.recyclerview"
+        minSdkVersion 23
+        targetSdkVersion 29
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+
+    viewBinding {
+        enabled true
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    implementation 'androidx.recyclerview:recyclerview:1.1.0'
+}
diff --git a/RecyclerView/app/proguard-rules.pro b/RecyclerView/app/proguard-rules.pro
new file mode 100644
index 0000000..f1b4245
--- /dev/null
+++ b/RecyclerView/app/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
diff --git a/RecyclerView/app/src/androidTest/java/com/example/recyclerview/ExampleInstrumentedTest.java b/RecyclerView/app/src/androidTest/java/com/example/recyclerview/ExampleInstrumentedTest.java
new file mode 100644
index 0000000..b23adae
--- /dev/null
+++ b/RecyclerView/app/src/androidTest/java/com/example/recyclerview/ExampleInstrumentedTest.java
@@ -0,0 +1,27 @@
+package com.example.recyclerview;
+
+import android.content.Context;
+
+import androidx.test.platform.app.InstrumentationRegistry;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+
+        assertEquals("com.example.recyclerview", appContext.getPackageName());
+    }
+}
diff --git a/RecyclerView/app/src/main/AndroidManifest.xml b/RecyclerView/app/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..9f45da5
--- /dev/null
+++ b/RecyclerView/app/src/main/AndroidManifest.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.recyclerview">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <activity android:name=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file
diff --git a/RecyclerView/app/src/main/java/com/example/recyclerview/Email.java b/RecyclerView/app/src/main/java/com/example/recyclerview/Email.java
new file mode 100644
index 0000000..5c87973
--- /dev/null
+++ b/RecyclerView/app/src/main/java/com/example/recyclerview/Email.java
@@ -0,0 +1,11 @@
+package com.example.recyclerview;
+
+class Email {
+    String mSender;
+    String mTitle;
+
+    public Email(String sender, String title) {
+        mSender = sender;
+        mTitle = title;
+    }
+}
diff --git a/RecyclerView/app/src/main/java/com/example/recyclerview/EmailAdapter.java b/RecyclerView/app/src/main/java/com/example/recyclerview/EmailAdapter.java
new file mode 100644
index 0000000..0aaf8d3
--- /dev/null
+++ b/RecyclerView/app/src/main/java/com/example/recyclerview/EmailAdapter.java
@@ -0,0 +1,59 @@
+package com.example.recyclerview;
+
+import android.content.Context;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+import com.example.recyclerview.databinding.ItemBinding;
+
+import java.util.List;
+
+class ViewHolder extends RecyclerView.ViewHolder {
+    ItemBinding mBinding;
+
+    ViewHolder(ItemBinding binding) {
+        super(binding.getRoot());
+        mBinding = binding;
+        mBinding.getRoot().setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                int i = getAdapterPosition();
+                if (i != RecyclerView.NO_POSITION)
+                    Log.i("RV", String.format("%d %s", i, mBinding.textSender.getText()));
+            }
+        });
+    }
+}
+
+public class EmailAdapter extends RecyclerView.Adapter<ViewHolder> {
+
+    private List<Email> mEmails;
+
+    EmailAdapter(List<Email> emails) {
+        mEmails = emails;
+    }
+
+    @NonNull
+    @Override
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        Context context = parent.getContext();
+        LayoutInflater inflater = LayoutInflater.from(context);
+        ItemBinding binding = ItemBinding.inflate(inflater, parent, false);
+        return new ViewHolder(binding);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
+        Email email = mEmails.get(position);
+        holder.mBinding.textSender.setText(email.mSender);
+        holder.mBinding.textTitle.setText(email.mTitle);
+    }
+
+    @Override
+    public int getItemCount() {
+        return mEmails.size();
+    }
+}
diff --git a/RecyclerView/app/src/main/java/com/example/recyclerview/MainActivity.java b/RecyclerView/app/src/main/java/com/example/recyclerview/MainActivity.java
new file mode 100644
index 0000000..8b7fd19
--- /dev/null
+++ b/RecyclerView/app/src/main/java/com/example/recyclerview/MainActivity.java
@@ -0,0 +1,40 @@
+package com.example.recyclerview;
+
+import android.os.Bundle;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.recyclerview.widget.LinearLayoutManager;
+
+import com.example.recyclerview.databinding.ActivityMainBinding;
+
+import java.util.ArrayList;
+
+public class MainActivity extends AppCompatActivity {
+
+    ArrayList<Email> mEmails = new ArrayList<>();
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        ActivityMainBinding binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+
+        makeListOfEmails();
+
+        EmailAdapter adapter = new EmailAdapter(mEmails);
+        binding.recyclerview.setAdapter(adapter);
+        binding.recyclerview.setLayoutManager(new LinearLayoutManager(this));
+        binding.recyclerview.setHasFixedSize(true);
+
+
+        mEmails.add(0, new Email("Friend", "Hello! Do you have ..."));
+        adapter.notifyItemInserted(0);
+    }
+
+    private void makeListOfEmails() {
+        String[] names = getResources().getStringArray(R.array.names);
+        for (String name : names)
+            mEmails.add(new Email(name, "Hello, friend. Do you have any idea about ..."));
+        for (String name : names)
+            mEmails.add(new Email(name, "Welcome home, friend. How was your trip?"));
+    }
+}
diff --git a/RecyclerView/app/src/main/res/drawable-v24/ic_launcher_foreground.xml b/RecyclerView/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
new file mode 100644
index 0000000..2b068d1
--- /dev/null
+++ b/RecyclerView/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path android:pathData="M31,63.928c0,0 6.4,-11 12.1,-13.1c7.2,-2.6 26,-1.4 26,-1.4l38.1,38.1L107,108.928l-32,-1L31,63.928z">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="85.84757"
+                android:endY="92.4963"
+                android:startX="42.9492"
+                android:startY="49.59793"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M65.3,45.828l3.8,-6.6c0.2,-0.4 0.1,-0.9 -0.3,-1.1c-0.4,-0.2 -0.9,-0.1 -1.1,0.3l-3.9,6.7c-6.3,-2.8 -13.4,-2.8 -19.7,0l-3.9,-6.7c-0.2,-0.4 -0.7,-0.5 -1.1,-0.3C38.8,38.328 38.7,38.828 38.9,39.228l3.8,6.6C36.2,49.428 31.7,56.028 31,63.928h46C76.3,56.028 71.8,49.428 65.3,45.828zM43.4,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2c-0.3,-0.7 -0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C45.3,56.528 44.5,57.328 43.4,57.328L43.4,57.328zM64.6,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2s-0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C66.5,56.528 65.6,57.328 64.6,57.328L64.6,57.328z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>
\ No newline at end of file
diff --git a/RecyclerView/app/src/main/res/drawable/ic_launcher_background.xml b/RecyclerView/app/src/main/res/drawable/ic_launcher_background.xml
new file mode 100644
index 0000000..07d5da9
--- /dev/null
+++ b/RecyclerView/app/src/main/res/drawable/ic_launcher_background.xml
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#3DDC84"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+</vector>
diff --git a/RecyclerView/app/src/main/res/drawable/ic_person_black_24dp.xml b/RecyclerView/app/src/main/res/drawable/ic_person_black_24dp.xml
new file mode 100644
index 0000000..74f64ac
--- /dev/null
+++ b/RecyclerView/app/src/main/res/drawable/ic_person_black_24dp.xml
@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#5DFF9A"
+    android:viewportHeight="24.0" android:viewportWidth="24.0"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="#FF000000" android:pathData="M12,12c2.21,0 4,-1.79 4,-4s-1.79,-4 -4,-4 -4,1.79 -4,4 1.79,4 4,4zM12,14c-2.67,0 -8,1.34 -8,4v2h16v-2c0,-2.66 -5.33,-4 -8,-4z"/>
+</vector>
diff --git a/RecyclerView/app/src/main/res/layout/activity_main.xml b/RecyclerView/app/src/main/res/layout/activity_main.xml
new file mode 100644
index 0000000..5f6e11b
--- /dev/null
+++ b/RecyclerView/app/src/main/res/layout/activity_main.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical"
+    tools:context="com.example.recyclerview.MainActivity">
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/recyclerview"
+        android:scrollbars="vertical"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+</LinearLayout>
diff --git a/RecyclerView/app/src/main/res/layout/item.xml b/RecyclerView/app/src/main/res/layout/item.xml
new file mode 100644
index 0000000..4562131
--- /dev/null
+++ b/RecyclerView/app/src/main/res/layout/item.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:orientation="horizontal"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content" >
+    <ImageView
+        android:layout_width="wrap_content"
+        android:layout_height="match_parent"
+        app:srcCompat="@drawable/ic_person_black_24dp"
+        android:contentDescription="@string/person" />
+
+    <TextView
+        android:id="@+id/textSender"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="1" />
+
+    <TextView
+        android:id="@+id/textTitle"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="2" />
+</LinearLayout>
diff --git a/RecyclerView/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml b/RecyclerView/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/RecyclerView/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/RecyclerView/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml b/RecyclerView/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/RecyclerView/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/RecyclerView/app/src/main/res/mipmap-hdpi/ic_launcher.png b/RecyclerView/app/src/main/res/mipmap-hdpi/ic_launcher.png
new file mode 100644
index 0000000..a571e60
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-hdpi/ic_launcher.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-hdpi/ic_launcher_round.png b/RecyclerView/app/src/main/res/mipmap-hdpi/ic_launcher_round.png
new file mode 100644
index 0000000..61da551
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-hdpi/ic_launcher_round.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-mdpi/ic_launcher.png b/RecyclerView/app/src/main/res/mipmap-mdpi/ic_launcher.png
new file mode 100644
index 0000000..c41dd28
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-mdpi/ic_launcher.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-mdpi/ic_launcher_round.png b/RecyclerView/app/src/main/res/mipmap-mdpi/ic_launcher_round.png
new file mode 100644
index 0000000..db5080a
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-mdpi/ic_launcher_round.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/RecyclerView/app/src/main/res/mipmap-xhdpi/ic_launcher.png
new file mode 100644
index 0000000..6dba46d
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-xhdpi/ic_launcher.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png b/RecyclerView/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..da31a87
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/RecyclerView/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
new file mode 100644
index 0000000..15ac681
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-xxhdpi/ic_launcher.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png b/RecyclerView/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..b216f2d
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/RecyclerView/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
new file mode 100644
index 0000000..f25a419
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ
diff --git a/RecyclerView/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png b/RecyclerView/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..e96783c
Binary files /dev/null and b/RecyclerView/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png differ
diff --git a/RecyclerView/app/src/main/res/values/arrays.xml b/RecyclerView/app/src/main/res/values/arrays.xml
new file mode 100644
index 0000000..f34d9b1
--- /dev/null
+++ b/RecyclerView/app/src/main/res/values/arrays.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string-array name="names">
+        <item>Emma</item>
+        <item>Olivia</item>
+        <item>Ava</item>
+        <item>Amelia</item>
+        <item>Isabella</item>
+        <item>Liam</item>
+        <item>Noah</item>
+        <item>William</item>
+        <item>Oliver</item>
+        <item>Lucas</item>
+    </string-array>
+</resources>
\ No newline at end of file
diff --git a/RecyclerView/app/src/main/res/values/colors.xml b/RecyclerView/app/src/main/res/values/colors.xml
new file mode 100644
index 0000000..030098f
--- /dev/null
+++ b/RecyclerView/app/src/main/res/values/colors.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="colorPrimary">#6200EE</color>
+    <color name="colorPrimaryDark">#3700B3</color>
+    <color name="colorAccent">#03DAC5</color>
+</resources>
diff --git a/RecyclerView/app/src/main/res/values/strings.xml b/RecyclerView/app/src/main/res/values/strings.xml
new file mode 100644
index 0000000..ac995a3
--- /dev/null
+++ b/RecyclerView/app/src/main/res/values/strings.xml
@@ -0,0 +1,5 @@
+<resources>
+    <string name="app_name">RecyclerView</string>
+    <string name="person">Person</string>
+    <string name="delete">Delete</string>
+</resources>
diff --git a/MaterialTest/app/src/main/res/values/styles.xml b/RecyclerView/app/src/main/res/values/styles.xml
similarity index 100%
rename from MaterialTest/app/src/main/res/values/styles.xml
rename to RecyclerView/app/src/main/res/values/styles.xml
diff --git a/RecyclerView/app/src/test/java/com/example/recyclerview/ExampleUnitTest.java b/RecyclerView/app/src/test/java/com/example/recyclerview/ExampleUnitTest.java
new file mode 100644
index 0000000..02f682c
--- /dev/null
+++ b/RecyclerView/app/src/test/java/com/example/recyclerview/ExampleUnitTest.java
@@ -0,0 +1,17 @@
+package com.example.recyclerview;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+public class ExampleUnitTest {
+    @Test
+    public void addition_isCorrect() {
+        assertEquals(4, 2 + 2);
+    }
+}
\ No newline at end of file
diff --git a/RecyclerView/build.gradle b/RecyclerView/build.gradle
new file mode 100644
index 0000000..a88f623
--- /dev/null
+++ b/RecyclerView/build.gradle
@@ -0,0 +1,29 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+
+buildscript {
+    
+    repositories {
+        google()
+        jcenter()
+        
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.6.3'
+        
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+        
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}
diff --git a/RecyclerView/gradle.properties b/RecyclerView/gradle.properties
new file mode 100644
index 0000000..199d16e
--- /dev/null
+++ b/RecyclerView/gradle.properties
@@ -0,0 +1,20 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx1536m
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
+
diff --git a/RecyclerView/gradle/wrapper/gradle-wrapper.jar b/RecyclerView/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..f6b961f
Binary files /dev/null and b/RecyclerView/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/RecyclerView/gradle/wrapper/gradle-wrapper.properties b/RecyclerView/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..22581d9
--- /dev/null
+++ b/RecyclerView/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Fri May 08 02:08:08 KST 2020
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
diff --git a/RecyclerView/gradlew b/RecyclerView/gradlew
new file mode 100644
index 0000000..cccdd3d
--- /dev/null
+++ b/RecyclerView/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/RecyclerView/gradlew.bat b/RecyclerView/gradlew.bat
new file mode 100644
index 0000000..f955316
--- /dev/null
+++ b/RecyclerView/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/RecyclerView/settings.gradle b/RecyclerView/settings.gradle
new file mode 100644
index 0000000..054cd83
--- /dev/null
+++ b/RecyclerView/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name='RecyclerView'
+include ':app'
diff --git a/Room/.gitignore b/Room/.gitignore
new file mode 100644
index 0000000..603b140
--- /dev/null
+++ b/Room/.gitignore
@@ -0,0 +1,14 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
diff --git a/Room/app/.gitignore b/Room/app/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/Room/app/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/Room/app/build.gradle b/Room/app/build.gradle
new file mode 100644
index 0000000..c1f765a
--- /dev/null
+++ b/Room/app/build.gradle
@@ -0,0 +1,49 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
+
+    defaultConfig {
+        applicationId "com.example.room"
+        minSdkVersion 23
+        targetSdkVersion 29
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+
+}
+
+ext {
+    roomVersion = '2.0.0-beta01'
+    archLifecycleVersion = '2.0.0-beta01'
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+
+    // Room components
+    implementation "androidx.room:room-runtime:$roomVersion"
+    annotationProcessor "androidx.room:room-compiler:$roomVersion"
+    androidTestImplementation "androidx.room:room-testing:$roomVersion"
+
+    // Lifecycle components
+    implementation "androidx.lifecycle:lifecycle-extensions:$archLifecycleVersion"
+    //noinspection LifecycleAnnotationProcessorWithJava8
+    annotationProcessor "androidx.lifecycle:lifecycle-compiler:$archLifecycleVersion"
+}
diff --git a/Room/app/proguard-rules.pro b/Room/app/proguard-rules.pro
new file mode 100644
index 0000000..f1b4245
--- /dev/null
+++ b/Room/app/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
diff --git a/Room/app/src/androidTest/java/com/example/room/ExampleInstrumentedTest.java b/Room/app/src/androidTest/java/com/example/room/ExampleInstrumentedTest.java
new file mode 100644
index 0000000..077c35e
--- /dev/null
+++ b/Room/app/src/androidTest/java/com/example/room/ExampleInstrumentedTest.java
@@ -0,0 +1,27 @@
+package com.example.room;
+
+import android.content.Context;
+
+import androidx.test.platform.app.InstrumentationRegistry;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+
+        assertEquals("com.example.room", appContext.getPackageName());
+    }
+}
diff --git a/MaterialTest/app/src/main/AndroidManifest.xml b/Room/app/src/main/AndroidManifest.xml
similarity index 87%
rename from MaterialTest/app/src/main/AndroidManifest.xml
rename to Room/app/src/main/AndroidManifest.xml
index c12ea8d..a60a606 100644
--- a/MaterialTest/app/src/main/AndroidManifest.xml
+++ b/Room/app/src/main/AndroidManifest.xml
@@ -1,11 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.jyheo.materialtest">
+    package="com.example.room">
 
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
         <activity android:name=".MainActivity">
diff --git a/Room/app/src/main/java/com/example/room/MainActivity.java b/Room/app/src/main/java/com/example/room/MainActivity.java
new file mode 100644
index 0000000..ad8d07c
--- /dev/null
+++ b/Room/app/src/main/java/com/example/room/MainActivity.java
@@ -0,0 +1,121 @@
+package com.example.room;
+
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.Observer;
+import android.os.AsyncTask;
+import android.os.Bundle;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AppCompatActivity;
+import android.view.View;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.TextView;
+
+import java.util.List;
+
+public class MainActivity extends AppCompatActivity {
+
+    private MyDao mMyDao;
+
+    private static class InsertTask extends AsyncTask<Student, Void, Void> {
+        private MyDao mMyDao;
+
+        InsertTask(MyDao dao) {
+            mMyDao = dao;
+        }
+
+        @Override
+        protected Void doInBackground(Student... params) {
+            mMyDao.insertStudent(params[0]);
+            return null;
+        }
+    }
+
+    private static class DeleteAllTask extends AsyncTask<Void, Void, Void> {
+        private MyDao mMyDao;
+
+        DeleteAllTask(MyDao dao) {
+            mMyDao = dao;
+        }
+
+        @Override
+        protected Void doInBackground(Void... params) {
+            mMyDao.deleteAllStudent();
+            return null;
+        }
+    }
+
+    private static class DeleteTask extends AsyncTask<Student, Void, Void> {
+        private MyDao mMyDao;
+
+        DeleteTask(MyDao dao) {
+            mMyDao = dao;
+        }
+
+        @Override
+        protected Void doInBackground(Student... params) {
+            mMyDao.deleteStudent(params[0]);
+            return null;
+        }
+    }
+
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+
+
+        MyRoomDatabase db = MyRoomDatabase.getDatabase(this);
+        mMyDao = db.getMyDao();
+        LiveData<List<Student>> mAllStudents = mMyDao.getAllStudents();
+
+        mAllStudents.observe(this, new Observer<List<Student>>() {
+            @Override
+            public void onChanged(@Nullable List<Student> students) {
+                if (students == null)
+                    return;
+                StringBuilder sb = new StringBuilder();
+
+                for (Student s : students) {
+                    sb.append(s.id); sb.append("-");
+                    sb.append(s.getName());
+                    sb.append("\n");
+                }
+                TextView listview = findViewById(R.id.listview);
+                listview.setText(sb.toString());
+            }
+        });
+
+        Button add = findViewById(R.id.add_student);
+        add.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                EditText edit_word = findViewById(R.id.edit_name);
+                String name = edit_word.getText().toString();
+                new InsertTask(mMyDao).execute(new Student(name));
+            }
+        });
+
+        Button delete = findViewById(R.id.delete);
+        delete.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                EditText student_id = findViewById(R.id.student_id);
+                Student student = new Student("");
+                student.id = Integer.valueOf(student_id.getText().toString());
+                new DeleteTask(mMyDao).execute(student);
+            }
+        });
+
+        Button delete_all = findViewById(R.id.deleteall);
+        delete_all.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                new DeleteAllTask(mMyDao).execute();
+            }
+        });
+    }
+}
diff --git a/Room/app/src/main/java/com/example/room/MyDao.java b/Room/app/src/main/java/com/example/room/MyDao.java
new file mode 100644
index 0000000..c574a5f
--- /dev/null
+++ b/Room/app/src/main/java/com/example/room/MyDao.java
@@ -0,0 +1,35 @@
+package com.example.room;
+
+import androidx.lifecycle.LiveData;
+import androidx.room.Dao;
+import androidx.room.Delete;
+import androidx.room.Insert;
+import androidx.room.OnConflictStrategy;
+import androidx.room.Query;
+
+import java.util.List;
+
+@Dao
+public interface MyDao {
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void insertStudent(Student student);
+
+    @Query("DELETE FROM student_table")
+    void deleteAllStudent();
+
+    @Query("SELECT * FROM student_table")
+    LiveData<List<Student>> getAllStudents();
+
+    @Query("SELECT * FROM student_table WHERE name = :sname")
+    LiveData<List<Student>> selectStduentByName(String sname);
+
+    @Delete
+    void deleteStudent(Student... student); // primary key is used to find the student
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void insertTeacher(Teacher teacher);
+
+    //@Query("SELECT ")
+}
+
diff --git a/Room/app/src/main/java/com/example/room/MyRoomDatabase.java b/Room/app/src/main/java/com/example/room/MyRoomDatabase.java
new file mode 100644
index 0000000..77910d4
--- /dev/null
+++ b/Room/app/src/main/java/com/example/room/MyRoomDatabase.java
@@ -0,0 +1,48 @@
+package com.example.room;
+
+import android.content.Context;
+
+import androidx.room.Database;
+import androidx.room.Room;
+import androidx.room.RoomDatabase;
+import androidx.room.migration.Migration;
+import androidx.sqlite.db.SupportSQLiteDatabase;
+
+@Database(entities = {Student.class, Teacher.class}, version = 2)
+public abstract class MyRoomDatabase extends RoomDatabase {
+
+    public abstract MyDao getMyDao();
+
+    private static volatile MyRoomDatabase INSTANCE;
+
+    private static final Migration MIGRATION_1_2 = new Migration(1, 2) {
+        @Override
+        public void migrate(SupportSQLiteDatabase database) {
+            // Since we didn't alter the table, there's nothing else to do here.
+        }
+    };
+
+    // It just shows the example of data migration
+    // see the post: https://medium.com/androiddevelopers/understanding-migrations-with-room-f01e04b07929
+    private static final Migration MIGRATION_2_3 = new Migration(2, 3) {
+        @Override
+        public void migrate(SupportSQLiteDatabase database) {
+            database.execSQL("ALTER TABLE student_table "
+                    + " ADD COLUMN last_update INTEGER");
+        }
+    };
+
+    static MyRoomDatabase getDatabase(final Context context) {
+        if (INSTANCE == null) {
+            synchronized (MyRoomDatabase.class) {
+                if (INSTANCE == null) {
+                    INSTANCE = Room.databaseBuilder(context.getApplicationContext(),
+                            MyRoomDatabase.class, "school_database")
+                            .addMigrations(MIGRATION_1_2)
+                            .build();
+                }
+            }
+        }
+        return INSTANCE;
+    }
+}
diff --git a/Room/app/src/main/java/com/example/room/Student.java b/Room/app/src/main/java/com/example/room/Student.java
new file mode 100644
index 0000000..e676bf3
--- /dev/null
+++ b/Room/app/src/main/java/com/example/room/Student.java
@@ -0,0 +1,21 @@
+package com.example.room;
+
+import androidx.annotation.NonNull;
+import androidx.room.ColumnInfo;
+import androidx.room.Entity;
+import androidx.room.PrimaryKey;
+
+@Entity(tableName = "student_table")
+public class Student {
+
+    @PrimaryKey(autoGenerate = true)
+    int id;
+
+    @NonNull
+    @ColumnInfo(name = "name")
+    private String mName;
+
+    Student(@NonNull String name) {mName = name;}
+
+    public String getName() {return mName;}
+}
diff --git a/Room/app/src/main/java/com/example/room/Teacher.java b/Room/app/src/main/java/com/example/room/Teacher.java
new file mode 100644
index 0000000..da503cd
--- /dev/null
+++ b/Room/app/src/main/java/com/example/room/Teacher.java
@@ -0,0 +1,27 @@
+package com.example.room;
+
+import androidx.annotation.NonNull;
+import androidx.room.ColumnInfo;
+import androidx.room.Entity;
+import androidx.room.PrimaryKey;
+
+@Entity(tableName = "teacher_table")
+public class Teacher {
+
+    @PrimaryKey(autoGenerate = true)
+    int id;
+
+    @NonNull @ColumnInfo(name = "name")
+    private String mName;
+
+    @NonNull @ColumnInfo(name = "position")
+    private String mPosition;
+
+    Teacher(@NonNull String name, @NonNull String position) {
+        mName = name;
+        mPosition = position;
+    }
+
+    public String getName() {return mName;}
+    public String getPosition() {return mPosition;}
+}
diff --git a/Room/app/src/main/res/drawable-v24/ic_launcher_foreground.xml b/Room/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
new file mode 100644
index 0000000..2b068d1
--- /dev/null
+++ b/Room/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path android:pathData="M31,63.928c0,0 6.4,-11 12.1,-13.1c7.2,-2.6 26,-1.4 26,-1.4l38.1,38.1L107,108.928l-32,-1L31,63.928z">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="85.84757"
+                android:endY="92.4963"
+                android:startX="42.9492"
+                android:startY="49.59793"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M65.3,45.828l3.8,-6.6c0.2,-0.4 0.1,-0.9 -0.3,-1.1c-0.4,-0.2 -0.9,-0.1 -1.1,0.3l-3.9,6.7c-6.3,-2.8 -13.4,-2.8 -19.7,0l-3.9,-6.7c-0.2,-0.4 -0.7,-0.5 -1.1,-0.3C38.8,38.328 38.7,38.828 38.9,39.228l3.8,6.6C36.2,49.428 31.7,56.028 31,63.928h46C76.3,56.028 71.8,49.428 65.3,45.828zM43.4,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2c-0.3,-0.7 -0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C45.3,56.528 44.5,57.328 43.4,57.328L43.4,57.328zM64.6,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2s-0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C66.5,56.528 65.6,57.328 64.6,57.328L64.6,57.328z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>
\ No newline at end of file
diff --git a/Room/app/src/main/res/drawable/ic_launcher_background.xml b/Room/app/src/main/res/drawable/ic_launcher_background.xml
new file mode 100644
index 0000000..07d5da9
--- /dev/null
+++ b/Room/app/src/main/res/drawable/ic_launcher_background.xml
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#3DDC84"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+</vector>
diff --git a/Room/app/src/main/res/layout/activity_main.xml b/Room/app/src/main/res/layout/activity_main.xml
new file mode 100644
index 0000000..3b2c6ef
--- /dev/null
+++ b/Room/app/src/main/res/layout/activity_main.xml
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical"
+    tools:context="com.example.roomexample.MainActivity">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal">
+        <EditText
+            android:id="@+id/edit_name"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"/>
+        <Button
+            android:id="@+id/add_student"
+            android:text="Add"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"/>
+
+    </LinearLayout>
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal">
+        <EditText
+            android:hint="id"
+            android:id="@+id/student_id"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"/>
+        <Button
+            android:id="@+id/delete"
+            android:text="Delete"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content" />
+        <Button
+            android:id="@+id/deleteall"
+            android:text="Delete All"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content" />
+    </LinearLayout>
+
+    <TextView
+        android:id="@+id/listview"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+</LinearLayout>
\ No newline at end of file
diff --git a/Room/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml b/Room/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/Room/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/Room/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml b/Room/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/Room/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/Room/app/src/main/res/mipmap-hdpi/ic_launcher.png b/Room/app/src/main/res/mipmap-hdpi/ic_launcher.png
new file mode 100644
index 0000000..a571e60
Binary files /dev/null and b/Room/app/src/main/res/mipmap-hdpi/ic_launcher.png differ
diff --git a/Room/app/src/main/res/mipmap-hdpi/ic_launcher_round.png b/Room/app/src/main/res/mipmap-hdpi/ic_launcher_round.png
new file mode 100644
index 0000000..61da551
Binary files /dev/null and b/Room/app/src/main/res/mipmap-hdpi/ic_launcher_round.png differ
diff --git a/Room/app/src/main/res/mipmap-mdpi/ic_launcher.png b/Room/app/src/main/res/mipmap-mdpi/ic_launcher.png
new file mode 100644
index 0000000..c41dd28
Binary files /dev/null and b/Room/app/src/main/res/mipmap-mdpi/ic_launcher.png differ
diff --git a/Room/app/src/main/res/mipmap-mdpi/ic_launcher_round.png b/Room/app/src/main/res/mipmap-mdpi/ic_launcher_round.png
new file mode 100644
index 0000000..db5080a
Binary files /dev/null and b/Room/app/src/main/res/mipmap-mdpi/ic_launcher_round.png differ
diff --git a/Room/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/Room/app/src/main/res/mipmap-xhdpi/ic_launcher.png
new file mode 100644
index 0000000..6dba46d
Binary files /dev/null and b/Room/app/src/main/res/mipmap-xhdpi/ic_launcher.png differ
diff --git a/Room/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png b/Room/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..da31a87
Binary files /dev/null and b/Room/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png differ
diff --git a/Room/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/Room/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
new file mode 100644
index 0000000..15ac681
Binary files /dev/null and b/Room/app/src/main/res/mipmap-xxhdpi/ic_launcher.png differ
diff --git a/Room/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png b/Room/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..b216f2d
Binary files /dev/null and b/Room/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png differ
diff --git a/Room/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/Room/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
new file mode 100644
index 0000000..f25a419
Binary files /dev/null and b/Room/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ
diff --git a/Room/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png b/Room/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..e96783c
Binary files /dev/null and b/Room/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png differ
diff --git a/Room/app/src/main/res/values/colors.xml b/Room/app/src/main/res/values/colors.xml
new file mode 100644
index 0000000..030098f
--- /dev/null
+++ b/Room/app/src/main/res/values/colors.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="colorPrimary">#6200EE</color>
+    <color name="colorPrimaryDark">#3700B3</color>
+    <color name="colorAccent">#03DAC5</color>
+</resources>
diff --git a/Room/app/src/main/res/values/strings.xml b/Room/app/src/main/res/values/strings.xml
new file mode 100644
index 0000000..7fdd662
--- /dev/null
+++ b/Room/app/src/main/res/values/strings.xml
@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">Room</string>
+</resources>
diff --git a/Room/app/src/main/res/values/styles.xml b/Room/app/src/main/res/values/styles.xml
new file mode 100644
index 0000000..5885930
--- /dev/null
+++ b/Room/app/src/main/res/values/styles.xml
@@ -0,0 +1,11 @@
+<resources>
+
+    <!-- Base application theme. -->
+    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+        <!-- Customize your theme here. -->
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+    </style>
+
+</resources>
diff --git a/Room/app/src/test/java/com/example/room/ExampleUnitTest.java b/Room/app/src/test/java/com/example/room/ExampleUnitTest.java
new file mode 100644
index 0000000..393a0b4
--- /dev/null
+++ b/Room/app/src/test/java/com/example/room/ExampleUnitTest.java
@@ -0,0 +1,17 @@
+package com.example.room;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+public class ExampleUnitTest {
+    @Test
+    public void addition_isCorrect() {
+        assertEquals(4, 2 + 2);
+    }
+}
\ No newline at end of file
diff --git a/Room/build.gradle b/Room/build.gradle
new file mode 100644
index 0000000..a88f623
--- /dev/null
+++ b/Room/build.gradle
@@ -0,0 +1,29 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+
+buildscript {
+    
+    repositories {
+        google()
+        jcenter()
+        
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.6.3'
+        
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+        
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}
diff --git a/Room/gradle.properties b/Room/gradle.properties
new file mode 100644
index 0000000..199d16e
--- /dev/null
+++ b/Room/gradle.properties
@@ -0,0 +1,20 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx1536m
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
+
diff --git a/Room/gradle/wrapper/gradle-wrapper.jar b/Room/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..f6b961f
Binary files /dev/null and b/Room/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/Room/gradle/wrapper/gradle-wrapper.properties b/Room/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..1967188
--- /dev/null
+++ b/Room/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Fri May 08 01:29:44 KST 2020
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
diff --git a/Room/gradlew b/Room/gradlew
new file mode 100644
index 0000000..cccdd3d
--- /dev/null
+++ b/Room/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/Room/gradlew.bat b/Room/gradlew.bat
new file mode 100644
index 0000000..f955316
--- /dev/null
+++ b/Room/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/Room/settings.gradle b/Room/settings.gradle
new file mode 100644
index 0000000..f1c7285
--- /dev/null
+++ b/Room/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name='Room'
+include ':app'
diff --git a/MaterialTest/.gitignore b/SensorTest/.gitignore
similarity index 82%
rename from MaterialTest/.gitignore
rename to SensorTest/.gitignore
index c6cbe56..39fb081 100644
--- a/MaterialTest/.gitignore
+++ b/SensorTest/.gitignore
@@ -6,3 +6,4 @@
 .DS_Store
 /build
 /captures
+.externalNativeBuild
diff --git a/SensorTest/app/.gitignore b/SensorTest/app/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/SensorTest/app/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/SensorTest/app/build.gradle b/SensorTest/app/build.gradle
new file mode 100644
index 0000000..3c7d856
--- /dev/null
+++ b/SensorTest/app/build.gradle
@@ -0,0 +1,29 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 26
+    defaultConfig {
+        applicationId "com.example.jyheo.sensortest"
+        minSdkVersion 22
+        targetSdkVersion 26
+        versionCode 1
+        versionName "1.0"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation 'com.android.support:appcompat-v7:26.1.0'
+    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
+    implementation 'pub.devrel:easypermissions:1.0.1'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'com.android.support.test:runner:1.0.1'
+    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
+}
diff --git a/SensorTest/app/proguard-rules.pro b/SensorTest/app/proguard-rules.pro
new file mode 100644
index 0000000..f1b4245
--- /dev/null
+++ b/SensorTest/app/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
diff --git a/SensorTest/app/src/androidTest/java/com/example/jyheo/sensortest/ExampleInstrumentedTest.java b/SensorTest/app/src/androidTest/java/com/example/jyheo/sensortest/ExampleInstrumentedTest.java
new file mode 100644
index 0000000..0d8004d
--- /dev/null
+++ b/SensorTest/app/src/androidTest/java/com/example/jyheo/sensortest/ExampleInstrumentedTest.java
@@ -0,0 +1,26 @@
+package com.example.jyheo.sensortest;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() throws Exception {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getTargetContext();
+
+        assertEquals("com.example.jyheo.sensortest", appContext.getPackageName());
+    }
+}
diff --git a/LocationAware/app/src/main/AndroidManifest.xml b/SensorTest/app/src/main/AndroidManifest.xml
similarity index 87%
rename from LocationAware/app/src/main/AndroidManifest.xml
rename to SensorTest/app/src/main/AndroidManifest.xml
index 0ca6723..25da86a 100644
--- a/LocationAware/app/src/main/AndroidManifest.xml
+++ b/SensorTest/app/src/main/AndroidManifest.xml
@@ -1,11 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.jyheo.locationaware">
+    package="com.example.jyheo.sensortest">
 
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
         <activity android:name=".MainActivity">
diff --git a/LocationAware/app/src/main/java/com/example/jyheo/locationaware/MainActivity.java b/SensorTest/app/src/main/java/com/example/jyheo/sensortest/MainActivity.java
similarity index 73%
rename from LocationAware/app/src/main/java/com/example/jyheo/locationaware/MainActivity.java
rename to SensorTest/app/src/main/java/com/example/jyheo/sensortest/MainActivity.java
index eb9f81a..8d80f1c 100644
--- a/LocationAware/app/src/main/java/com/example/jyheo/locationaware/MainActivity.java
+++ b/SensorTest/app/src/main/java/com/example/jyheo/sensortest/MainActivity.java
@@ -1,4 +1,4 @@
-package com.example.jyheo.locationaware;
+package com.example.jyheo.sensortest;
 
 import android.Manifest;
 import android.content.Context;
@@ -10,16 +10,20 @@
 import android.location.Location;
 import android.location.LocationListener;
 import android.location.LocationManager;
-import android.support.v4.app.ActivityCompat;
 import android.support.v4.content.ContextCompat;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.util.Log;
 import android.widget.TextView;
 
+import java.util.List;
+
 import pub.devrel.easypermissions.AfterPermissionGranted;
 import pub.devrel.easypermissions.EasyPermissions;
 
-public class MainActivity extends AppCompatActivity implements SensorEventListener {
+import static java.lang.Math.round;
+
+public class MainActivity extends AppCompatActivity implements LocationListener, SensorEventListener {
 
     private final static int MIN_TIME = 50;
     private final static int MIN_DIST = 100;
@@ -27,11 +31,11 @@ public class MainActivity extends AppCompatActivity implements SensorEventListen
 
     private LocationManager mLm;
     private TextView mLocationText;
-    private LocationListener mLocationListener;
 
     private TextView mAccel;
     private TextView mGyro;
     private TextView mMagnet;
+    private TextView mSensorList;
 
     SensorManager mSm;
 
@@ -44,37 +48,38 @@ protected void onCreate(Bundle savedInstanceState) {
         mAccel = (TextView) findViewById(R.id.tvAccelerometer);
         mGyro = (TextView) findViewById(R.id.tvGyroscope);
         mMagnet = (TextView) findViewById(R.id.tvMagnetic);
+        mSensorList = (TextView) findViewById(R.id.tvSensorList);
 
         mLm = (LocationManager) getSystemService(LOCATION_SERVICE);
+        mSm = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
+        List<Sensor> sensors = mSm.getSensorList(Sensor.TYPE_ALL);
+        StringBuilder sb = new StringBuilder();
+        for (Sensor s : sensors)
+            sb.append(s.getName()).append(":").append(s.getType()).append("\n");
+        mSensorList.setText(sb);
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        // Forward results to EasyPermissions
+        EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
     }
 
     @Override
+    @SuppressWarnings("MissingPermission")
     @AfterPermissionGranted(MY_PERMISSIONS_REQUEST_FINE_LOCATION)
     protected void onStart() {
         super.onStart();
-        mLocationListener = new LocationListener() {
-            public void onLocationChanged(Location location) {
-                //when location changed change text
-                mLocationText.setText("Location is long:" + round(location.getLongitude()) +
-                        " and lat:" + round(location.getLatitude()));
-            }
-
-            public void onStatusChanged(String provider, int status, Bundle extras) {}
-
-            public void onProviderEnabled(String provider) {}
-
-            public void onProviderDisabled(String provider) {}
-        };
-
-        //note that LocationManager.NETWORK_PROVIDER will not work on the emulator because mock
-        //location data is injected as GPS location data
 
         String[] perms = {Manifest.permission.ACCESS_FINE_LOCATION};
         if (EasyPermissions.hasPermissions(this, perms)) {
             // Already have permission, do the thing
             try {
+                Location loc = mLm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
+                onLocationChanged(loc);
                 mLm.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME, MIN_DIST,
-                        mLocationListener);
+                        this);
             } catch(SecurityException e) {  // just remove warning message!
             }
         } else {
@@ -83,22 +88,31 @@ public void onProviderDisabled(String provider) {}
                     MY_PERMISSIONS_REQUEST_FINE_LOCATION, perms);
         }
 
-        mSm = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
         Sensor accelSensor = mSm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
         Sensor gyroSensor = mSm.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
         Sensor magnetSensor = mSm.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
+
         mSm.registerListener(this, accelSensor, SensorManager.SENSOR_DELAY_NORMAL);
         mSm.registerListener(this, gyroSensor, SensorManager.SENSOR_DELAY_NORMAL);
         mSm.registerListener(this, magnetSensor, SensorManager.SENSOR_DELAY_NORMAL);
-
     }
 
     @Override
-    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
-        // Forward results to EasyPermissions
-        EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
+    public void onLocationChanged(Location location) {
+        //when location changed change text
+        mLocationText.setText("Location is long:" + location.getLongitude() +
+                " and lat:" + location.getLatitude());
     }
 
+    @Override
+    public void onStatusChanged(String provider, int status, Bundle extras) {}
+
+    @Override
+    public void onProviderEnabled(String provider) {}
+
+    @Override
+    public void onProviderDisabled(String provider) {}
+
     @Override
     public void onSensorChanged(SensorEvent event) {
         switch(event.sensor.getType()){
@@ -115,22 +129,18 @@ public void onSensorChanged(SensorEvent event) {
     }
 
     @Override
-    public void onAccuracyChanged(Sensor sensor, int accuracy) {
-
-    }
+    public void onAccuracyChanged(Sensor sensor, int accuracy) {}
 
     @Override
+    @SuppressWarnings("MissingPermission")
     protected void onStop() {
         super.onStop();
         if (ContextCompat.checkSelfPermission(this,
                 Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
-            mLm.removeUpdates(mLocationListener);
+            mLm.removeUpdates(this);
         }
 
         mSm.unregisterListener(this);
     }
 
-    private String round(double toRound) {
-        return String.format("%.2f", toRound);
-    }
 }
diff --git a/SensorTest/app/src/main/res/drawable-v24/ic_launcher_foreground.xml b/SensorTest/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
new file mode 100644
index 0000000..c7bd21d
--- /dev/null
+++ b/SensorTest/app/src/main/res/drawable-v24/ic_launcher_foreground.xml
@@ -0,0 +1,34 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+    <path
+        android:fillType="evenOdd"
+        android:pathData="M32,64C32,64 38.39,52.99 44.13,50.95C51.37,48.37 70.14,49.57 70.14,49.57L108.26,87.69L108,109.01L75.97,107.97L32,64Z"
+        android:strokeColor="#00000000"
+        android:strokeWidth="1">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="78.5885"
+                android:endY="90.9159"
+                android:startX="48.7653"
+                android:startY="61.0927"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M66.94,46.02L66.94,46.02C72.44,50.07 76,56.61 76,64L32,64C32,56.61 35.56,50.11 40.98,46.06L36.18,41.19C35.45,40.45 35.45,39.3 36.18,38.56C36.91,37.81 38.05,37.81 38.78,38.56L44.25,44.05C47.18,42.57 50.48,41.71 54,41.71C57.48,41.71 60.78,42.57 63.68,44.05L69.11,38.56C69.84,37.81 70.98,37.81 71.71,38.56C72.44,39.3 72.44,40.45 71.71,41.19L66.94,46.02ZM62.94,56.92C64.08,56.92 65,56.01 65,54.88C65,53.76 64.08,52.85 62.94,52.85C61.8,52.85 60.88,53.76 60.88,54.88C60.88,56.01 61.8,56.92 62.94,56.92ZM45.06,56.92C46.2,56.92 47.13,56.01 47.13,54.88C47.13,53.76 46.2,52.85 45.06,52.85C43.92,52.85 43,53.76 43,54.88C43,56.01 43.92,56.92 45.06,56.92Z"
+        android:strokeColor="#00000000"
+        android:strokeWidth="1" />
+</vector>
diff --git a/SensorTest/app/src/main/res/drawable/ic_launcher_background.xml b/SensorTest/app/src/main/res/drawable/ic_launcher_background.xml
new file mode 100644
index 0000000..d5fccc5
--- /dev/null
+++ b/SensorTest/app/src/main/res/drawable/ic_launcher_background.xml
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+    <path
+        android:fillColor="#26A69A"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeColor="#33FFFFFF"
+        android:strokeWidth="0.8" />
+</vector>
diff --git a/LocationAware/app/src/main/res/layout/activity_main.xml b/SensorTest/app/src/main/res/layout/activity_main.xml
similarity index 62%
rename from LocationAware/app/src/main/res/layout/activity_main.xml
rename to SensorTest/app/src/main/res/layout/activity_main.xml
index 0940563..9562fb7 100644
--- a/LocationAware/app/src/main/res/layout/activity_main.xml
+++ b/SensorTest/app/src/main/res/layout/activity_main.xml
@@ -4,52 +4,47 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
-    android:paddingBottom="@dimen/activity_vertical_margin"
-    android:paddingLeft="@dimen/activity_horizontal_margin"
-    android:paddingRight="@dimen/activity_horizontal_margin"
-    android:paddingTop="@dimen/activity_vertical_margin"
-    tools:context="com.example.jyheo.locationaware.MainActivity">
+    android:padding="16dp"
+    tools:context="com.example.jyheo.sensortest.MainActivity">
 
     <TextView
         android:id="@+id/tvLocation"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_margin="@dimen/activity_vertical_margin"
-        android:text="Hello World!" />
+        android:text="Location:" />
 
     <TextView
         android:text="@string/label_accelerometer"
         android:layout_width="wrap_content"
-        android:layout_margin="@dimen/activity_vertical_margin"
         android:layout_height="wrap_content" />
 
     <TextView
         android:id="@+id/tvAccelerometer"
         android:layout_width="wrap_content"
-        android:layout_margin="@dimen/activity_vertical_margin"
         android:layout_height="wrap_content" />
 
     <TextView
         android:text="@string/label_gyroscope"
         android:layout_width="wrap_content"
-        android:layout_margin="@dimen/activity_vertical_margin"
         android:layout_height="wrap_content" />
 
     <TextView
         android:id="@+id/tvGyroscope"
         android:layout_width="wrap_content"
-        android:layout_margin="@dimen/activity_vertical_margin"
         android:layout_height="wrap_content" />
 
     <TextView
         android:text="@string/label_magnetic_field"
         android:layout_width="wrap_content"
-        android:layout_margin="@dimen/activity_vertical_margin"
         android:layout_height="wrap_content" />
 
     <TextView
         android:id="@+id/tvMagnetic"
         android:layout_width="wrap_content"
-        android:layout_margin="@dimen/activity_vertical_margin"
+        android:layout_height="wrap_content" />
+
+    <TextView
+        android:id="@+id/tvSensorList"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content" />
 </LinearLayout>
diff --git a/SensorTest/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml b/SensorTest/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/SensorTest/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/SensorTest/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml b/SensorTest/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
new file mode 100644
index 0000000..eca70cf
--- /dev/null
+++ b/SensorTest/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>
\ No newline at end of file
diff --git a/SensorTest/app/src/main/res/mipmap-hdpi/ic_launcher.png b/SensorTest/app/src/main/res/mipmap-hdpi/ic_launcher.png
new file mode 100644
index 0000000..a2f5908
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-hdpi/ic_launcher.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-hdpi/ic_launcher_round.png b/SensorTest/app/src/main/res/mipmap-hdpi/ic_launcher_round.png
new file mode 100644
index 0000000..1b52399
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-hdpi/ic_launcher_round.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-mdpi/ic_launcher.png b/SensorTest/app/src/main/res/mipmap-mdpi/ic_launcher.png
new file mode 100644
index 0000000..ff10afd
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-mdpi/ic_launcher.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-mdpi/ic_launcher_round.png b/SensorTest/app/src/main/res/mipmap-mdpi/ic_launcher_round.png
new file mode 100644
index 0000000..115a4c7
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-mdpi/ic_launcher_round.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/SensorTest/app/src/main/res/mipmap-xhdpi/ic_launcher.png
new file mode 100644
index 0000000..dcd3cd8
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-xhdpi/ic_launcher.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png b/SensorTest/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..459ca60
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/SensorTest/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
new file mode 100644
index 0000000..8ca12fe
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-xxhdpi/ic_launcher.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png b/SensorTest/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..8e19b41
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/SensorTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
new file mode 100644
index 0000000..b824ebd
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ
diff --git a/SensorTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png b/SensorTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
new file mode 100644
index 0000000..4c19a13
Binary files /dev/null and b/SensorTest/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png differ
diff --git a/MaterialTest/app/src/main/res/values/colors.xml b/SensorTest/app/src/main/res/values/colors.xml
similarity index 61%
rename from MaterialTest/app/src/main/res/values/colors.xml
rename to SensorTest/app/src/main/res/values/colors.xml
index d3ce752..3ab3e9c 100644
--- a/MaterialTest/app/src/main/res/values/colors.xml
+++ b/SensorTest/app/src/main/res/values/colors.xml
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <!--<color name="colorPrimary">#3F51B5</color>-->
-    <color name="colorPrimary">#b53fab</color>
+    <color name="colorPrimary">#3F51B5</color>
     <color name="colorPrimaryDark">#303F9F</color>
     <color name="colorAccent">#FF4081</color>
 </resources>
diff --git a/LocationAware/app/src/main/res/values/strings.xml b/SensorTest/app/src/main/res/values/strings.xml
similarity index 67%
rename from LocationAware/app/src/main/res/values/strings.xml
rename to SensorTest/app/src/main/res/values/strings.xml
index 63b94f6..c477a3d 100644
--- a/LocationAware/app/src/main/res/values/strings.xml
+++ b/SensorTest/app/src/main/res/values/strings.xml
@@ -1,6 +1,5 @@
 <resources>
-    <string name="app_name">LocationAware</string>
-    <string name="action_settings">Settings</string>
+    <string name="app_name">SensorTest</string>
     <string name="label_accelerometer">Accelerometer data</string>
     <string name="label_gyroscope">Gyroscope data</string>
     <string name="label_magnetic_field">Magnetic data</string>
diff --git a/SensorTest/app/src/main/res/values/styles.xml b/SensorTest/app/src/main/res/values/styles.xml
new file mode 100644
index 0000000..5885930
--- /dev/null
+++ b/SensorTest/app/src/main/res/values/styles.xml
@@ -0,0 +1,11 @@
+<resources>
+
+    <!-- Base application theme. -->
+    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+        <!-- Customize your theme here. -->
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+    </style>
+
+</resources>
diff --git a/LocationAware/app/src/test/java/com/example/jyheo/locationaware/ExampleUnitTest.java b/SensorTest/app/src/test/java/com/example/jyheo/sensortest/ExampleUnitTest.java
similarity index 50%
rename from LocationAware/app/src/test/java/com/example/jyheo/locationaware/ExampleUnitTest.java
rename to SensorTest/app/src/test/java/com/example/jyheo/sensortest/ExampleUnitTest.java
index 6071203..9355dbd 100644
--- a/LocationAware/app/src/test/java/com/example/jyheo/locationaware/ExampleUnitTest.java
+++ b/SensorTest/app/src/test/java/com/example/jyheo/sensortest/ExampleUnitTest.java
@@ -1,11 +1,13 @@
-package com.example.jyheo.locationaware;
+package com.example.jyheo.sensortest;
 
 import org.junit.Test;
 
 import static org.junit.Assert.*;
 
 /**
- * To work on unit tests, switch the Test Artifact in the Build Variants view.
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
  */
 public class ExampleUnitTest {
     @Test
diff --git a/SensorTest/build.gradle b/SensorTest/build.gradle
new file mode 100644
index 0000000..020eae2
--- /dev/null
+++ b/SensorTest/build.gradle
@@ -0,0 +1,27 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+
+buildscript {
+    
+    repositories {
+        google()
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.0.0'
+        
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}
diff --git a/MaterialTest/gradle.properties b/SensorTest/gradle.properties
similarity index 78%
rename from MaterialTest/gradle.properties
rename to SensorTest/gradle.properties
index 1d3591c..aac7c9b 100644
--- a/MaterialTest/gradle.properties
+++ b/SensorTest/gradle.properties
@@ -9,10 +9,9 @@
 
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-# Default value: -Xmx10248m -XX:MaxPermSize=256m
-# org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
+org.gradle.jvmargs=-Xmx1536m
 
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
\ No newline at end of file
+# org.gradle.parallel=true
diff --git a/MaterialTest/gradle/wrapper/gradle-wrapper.jar b/SensorTest/gradle/wrapper/gradle-wrapper.jar
similarity index 100%
rename from MaterialTest/gradle/wrapper/gradle-wrapper.jar
rename to SensorTest/gradle/wrapper/gradle-wrapper.jar
diff --git a/SensorTest/gradle/wrapper/gradle-wrapper.properties b/SensorTest/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..5969bd5
--- /dev/null
+++ b/SensorTest/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Fri Nov 17 22:25:00 KST 2017
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
diff --git a/MaterialTest/gradlew b/SensorTest/gradlew
similarity index 100%
rename from MaterialTest/gradlew
rename to SensorTest/gradlew
diff --git a/MaterialTest/gradlew.bat b/SensorTest/gradlew.bat
similarity index 100%
rename from MaterialTest/gradlew.bat
rename to SensorTest/gradlew.bat
diff --git a/LocationAware/settings.gradle b/SensorTest/settings.gradle
similarity index 100%
rename from LocationAware/settings.gradle
rename to SensorTest/settings.gradle