week 6 and 7 resources

rdesmond · rdesmond · commit e0f8cd1b8a86 · 2025-08-01T16:04:19.000-06:00
diff --git a/week_6/IO/CSVReader.java b/week_6/IO/CSVReader.java
@@ -1,4 +1,6 @@
-package week_6;
+package week_6.IO;
+
+import week_6.generics.Student;
 
 import java.io.*;
 import java.util.ArrayList;
@@ -14,7 +16,7 @@ public static void main(String[] args) {
 
         try {
             reader = new BufferedReader(
-                    new FileReader("week_6/students.csv"));
+                    new FileReader("week_6/IO/students.csv"));
             String line = "";
             while ((line = reader.readLine()) != null) {
                 // print out the line that was just read
@@ -57,7 +59,7 @@ public static void main(String[] args) {
 
         if (!badData.isEmpty()){
 
-            try (FileWriter writer = new FileWriter("week_6/bad_data.txt")) {
+            try (FileWriter writer = new FileWriter("week_6/IO/bad_data.txt")) {
                for(String s : badData) {
                    writer.write(s);
                }
diff --git a/week_6/IO/CustomExceptionDemo.java b/week_6/IO/CustomExceptionDemo.java
@@ -1,4 +1,4 @@
-package week_6;
+package week_6.IO;
 
 public class CustomExceptionDemo extends Exception{
 
diff --git a/week_6/IO/ExceptionHandlingDemo.java b/week_6/IO/ExceptionHandlingDemo.java
@@ -1,4 +1,4 @@
-package week_6;
+package week_6.IO;
 
 public class ExceptionHandlingDemo {
 
diff --git a/week_6/IO/ReadFile.java b/week_6/IO/ReadFile.java
@@ -1,11 +1,11 @@
-package week_6;
+package week_6.IO;
 
 import java.io.BufferedReader;
 import java.io.FileReader;
 
 public class ReadFile {
     public static void main(String[] args) {
-        try (BufferedReader reader = new BufferedReader(new FileReader("week_6/itsworking.txt"))) {
+        try (BufferedReader reader = new BufferedReader(new FileReader("week_6/IO/itsworking.txt"))) {
             String line;
             while ((line = reader.readLine()) != null)
                 System.out.println(line);
diff --git a/week_6/IO/WriteFile.java b/week_6/IO/WriteFile.java
@@ -1,4 +1,4 @@
-package week_6;
+package week_6.IO;
 
 import java.io.FileWriter;
 import java.io.IOException;
diff --git a/week_6/IO/bad_data.txt b/week_6/IO/bad_data.txt
diff --git a/week_6/IO/itsworking.txt b/week_6/IO/itsworking.txt
diff --git a/week_6/IO/students.csv b/week_6/IO/students.csv
diff --git a/week_6/Student.java b/week_6/Student.java
diff --git a/week_6/generics/CustomGeneric.java b/week_6/generics/CustomGeneric.java
@@ -0,0 +1,18 @@
+package week_6.generics;
+
+public class CustomGeneric<T> {
+
+    private T val;
+
+    public CustomGeneric(T val){
+        this.val = val;
+    }
+
+    public T getVal() {
+        return val;
+    }
+
+    public void setVal(T val) {
+        this.val = val;
+    }
+}
diff --git a/week_6/generics/GenericMethods.java b/week_6/generics/GenericMethods.java
@@ -0,0 +1,25 @@
+package week_6.generics;
+
+public class GenericMethods {
+
+    public static void main(String[] args) {
+        double val1 = addNums(3, 3.14);
+        long l = 76146751461l;
+        float f = 7687565.45867f;
+
+        double val2 = addNums(l, f);
+        System.out.println(val2);
+
+    }
+
+    public static <N extends Number, M extends Number> double addNums (N num1, M num2){
+
+        double val = num1.doubleValue() + num2.doubleValue();
+        return val;
+
+    }
+
+    public static <N extends Number> N sumGen(N val1, N val2){
+        return val1;
+    }
+}
diff --git a/week_6/generics/GenericsDemo.java b/week_6/generics/GenericsDemo.java
@@ -1,4 +1,4 @@
-package week_6;
+package week_6.generics;
 
 import java.util.ArrayList;
 
@@ -9,6 +9,9 @@ public static void main(String[] args) {
         ArrayList<String> words = new ArrayList<>();
         words.add("Hello!");
 
+        // won't work
+        // words.add(8);
+
         ArrayList<Integer> nums = new ArrayList<>();
         nums.add(3);
 
@@ -19,6 +22,17 @@ public static void main(String[] args) {
         s.gpa = 3.9;
         students.add(s);
 
-    }
+        CustomGeneric<String> g1 = new CustomGeneric<>("String");
+        String str = g1.getVal();
+        System.out.println(str);
+        g1.setVal("String2");
+        System.out.println(g1.getVal());
 
+        CustomGeneric<Integer> g2 = new CustomGeneric<>(89);
+        int num = g2.getVal();
+        System.out.println(num);
+        g2.setVal(90);
+        System.out.println(str);
+
+    }
 }
diff --git a/week_6/generics/Student.java b/week_6/generics/Student.java
@@ -0,0 +1,7 @@
+package week_6.generics;
+
+public class Student {
+    public String name;
+    public String email;
+    public double gpa;
+}
diff --git a/week_7/Week_7.md b/week_7/Week_7.md
@@ -122,14 +122,23 @@ r.run();
 ## Quiz Questions
 
 1. **What is the difference between `start()` and `run()` in a Thread?**
+start() begins the execution - we call start() on a thread we want to start
+run() is called automatically by the Thread class after we start() it
 
 2. **What keyword is used to make a method thread-safe?**
+synchronized
 
 3. **What is a lambda expression?**
+A lambda expression consist of an arrow that points to a body
+That body (after the arrow) is the implementation of the abstract method
+coming from the Functional Interface that you're using.
+An anonymous function.
 
-4. **Which interface would you use to evaluate a condition?**
+4. **Which functional interface (FI) would you use to evaluate a condition?**
+Any type of Predicate FI
 
 5. **What is the output of `() -> System.out.println("Hi")`?**
+Hi 
 
 6. **What is the purpose of method references like `System.out::println`?**
 
diff --git a/week_7/functional/LambdaDemo.java b/week_7/functional/LambdaDemo.java
@@ -0,0 +1,58 @@
+package week_7.functional;
+
+import java.util.function.BiFunction;
+import java.util.function.Predicate;
+
+public class LambdaDemo {
+
+    public static void main(String[] args) {
+
+        // traditional interface
+        TraditionalInterfaceImpl obj = new TraditionalInterfaceImpl();
+        obj.doAThing();
+
+        // abstract inner class
+        TraditionalInterface obj2 = new TraditionalInterface() {
+            @Override
+            public void doAThing() {
+                System.out.println("abstract inner class doing a thing");
+
+            }
+
+            @Override
+            public void someThingElse() {
+                System.out.println("abstract inner class doing something else");
+
+            }
+        };
+        obj2.doAThing();
+
+        // lambda expression equivolent
+        SomeInterface<String> lamba1 = (String thing)
+                -> System.out.println("lambda doing a thing -> " + thing);
+
+        lamba1.doSomething("lambda things");
+
+        SomeInterface<Integer> lamba2 = (Integer num) -> {
+            System.out.println(num + num);
+            System.out.println(num * num);
+            System.out.println((num * 2) / num);
+            System.out.println("dancing all night long");
+        };
+
+        Predicate<String> predicate = (String s) -> args.length > 10 ;
+        System.out.println(predicate.test("hello")); // false
+        System.out.println(predicate.test("iuoaogouyafgutsdfiuga")); // true
+
+        lamba2.doSomething(78);
+
+        BiFunction<Integer, Double, String> biFun = (Integer i, Double d) -> {
+            Double x = i.doubleValue() + d.doubleValue();
+            return x.toString();
+        };
+
+        String result = biFun.apply(34, 98.76);
+        System.out.println("result = " + result);
+    }
+
+}
diff --git a/week_7/functional/SomeInterface.java b/week_7/functional/SomeInterface.java
@@ -0,0 +1,9 @@
+package week_7.functional;
+
+@FunctionalInterface
+// required to have one AND ONLY one abstract method
+public interface SomeInterface<T> {
+
+    public void doSomething(T s);
+
+}
diff --git a/week_7/functional/TraditionalInterface.java b/week_7/functional/TraditionalInterface.java
@@ -0,0 +1,8 @@
+package week_7.functional;
+
+public interface TraditionalInterface {
+
+    public void doAThing();
+    public void someThingElse();
+
+}
diff --git a/week_7/functional/TraditionalInterfaceImpl.java b/week_7/functional/TraditionalInterfaceImpl.java
@@ -0,0 +1,14 @@
+package week_7.functional;
+
+public class TraditionalInterfaceImpl implements TraditionalInterface{
+
+    @Override
+    public void doAThing() {
+        System.out.println("doing a thing");
+    }
+
+    @Override
+    public void someThingElse() {
+        System.out.println("doing something else");
+    }
+}
diff --git a/week_7/multithreading/MultithreadingDemo.java b/week_7/multithreading/MultithreadingDemo.java
@@ -0,0 +1,26 @@
+package week_7.multithreading;
+
+public class MultithreadingDemo {
+
+    public static void main(String[] args) throws InterruptedException {
+
+        System.out.println("starting main() method");
+
+        MyRunnable r1 = new MyRunnable();
+        Thread t1 = new Thread(r1);
+        t1.setPriority(1);
+        t1.start();
+
+        MyThread myThread = new MyThread("t1");
+        myThread.setPriority(5);
+        myThread.start();
+
+        t1.join();
+        myThread.join();
+
+
+        System.out.println("ending main() method");
+
+    }
+
+}
diff --git a/week_7/multithreading/MyRunnable.java b/week_7/multithreading/MyRunnable.java
@@ -0,0 +1,19 @@
+package week_7.multithreading;
+
+// retains the ability to extend another class
+public class MyRunnable implements Runnable {
+
+    @Override
+    public void run() {
+        // everything in here executed on it's own thread
+        for (int i = 0; i < 5; i++) {
+            System.out.println("In MyRunnable " + Thread.currentThread().getName() + ": i = " + i);
+
+            try {
+                Thread.currentThread().sleep(1000);
+            } catch (InterruptedException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+}
diff --git a/week_7/multithreading/MyThread.java b/week_7/multithreading/MyThread.java
@@ -0,0 +1,22 @@
+package week_7.multithreading;
+
+public class MyThread extends Thread {
+
+    public MyThread(String name){
+        super(name);
+    }
+
+    @Override
+    public void run(){
+        // everything in here executed on it's own thread
+        for (int i = 0; i < 5; i++) {
+            System.out.println("In MyThread " + getName() + ": i = " + i);
+
+            try {
+                Thread.currentThread().sleep(1000);
+            } catch (InterruptedException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-package week_6;`
	`1`	`+package week_6.IO;`
`2`	`2`
`3`	`3`	`public class CustomExceptionDemo extends Exception{`
`4`	`4`