Add TestWriter

Doha2012 · Doha2012 · commit f32730e8a30b · 2014-09-28T09:39:26.000+02:00
TestWriter contain methods used in Article Java - Write to file
diff --git a/core-java/src/test/java/org/baeldung/java/io/TestWriter.java b/core-java/src/test/java/org/baeldung/java/io/TestWriter.java
@@ -0,0 +1,202 @@
+package test;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.RandomAccessFile;
+import java.util.List;
+
+import au.com.bytecode.opencsv.CSVReader;
+import au.com.bytecode.opencsv.CSVWriter;
+import main.Foo;
+import junit.framework.TestCase;
+
+public class TestWriter extends TestCase {
+
+    private String fileName1 = "test1.txt";
+    private String fileName2 = "test2.txt";
+    private String fileName3 = "test3.txt";
+    private String fileName4 = "test4.csv";
+
+    public TestWriter(String name) {
+        super(name);
+    }
+
+    protected void setUp() throws Exception {
+        super.setUp();
+    }
+
+    protected void tearDown() throws Exception {
+        super.tearDown();
+    }
+
+    public void testWriteDouble_thenReadIt_shouldBeTheSame() {
+        double value = 2.5;
+        testWriteDouble(value);
+        assertEquals(value, testReadDouble(), 0.0000001);
+    }
+
+    public void testWriteToPosition_editValueIfSpecificPos_shouldChange() {
+        int data1 = 2014;
+        int data2 = 1500;
+        testWriteToPosition(data1, 4);
+        assertEquals(data1, testReadFromPosition(4));
+        testWriteToPosition(data2, 4);
+        assertEquals(data2, testReadFromPosition(4));
+    }
+
+    public void testWriteObject_thenReadIt_instanceVariableValuesShouldBeTheSame() {
+        Foo foo = new Foo(1, "John");
+        testWriteObject(foo);
+        Foo read = testReadObject();
+        assertEquals(foo.getId(), read.getId());
+        assertEquals(foo.getName(), read.getName());
+    }
+
+    public void testWriteCSVReport_thenReadAllData_shouldBeTheSame() {
+        Foo[] arr = new Foo[3];
+        arr[0] = new Foo(1, "John");
+        arr[1] = new Foo(2, "Adam");
+        arr[2] = new Foo(3, "Jane");
+        testWriteCSVReport(arr);
+        Foo[] read = testReadCSVReport();
+        assertEquals(arr[0].getId(), read[0].getId());
+        assertEquals(arr[2].getName(), read[2].getName());
+        assertEquals(arr[1].getId(), read[1].getId());
+    }
+//================= writer methods========
+ // use DataOutputStream to write primitive data types
+    public void testWriteDouble(double value) {
+        DataOutputStream stream;
+        try {
+            FileOutputStream fos = new FileOutputStream(fileName1);
+            stream = new DataOutputStream(new BufferedOutputStream(fos));
+            stream.writeDouble(value);
+            stream.close();
+        } catch (Exception e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+    }
+
+    // use RandomAccessFile to write data at specific position in the file
+    public void testWriteToPosition(int data, long position) {
+        try {
+            RandomAccessFile writer = new RandomAccessFile(fileName2, "rw");
+            writer.seek(position);
+            writer.writeInt(data);
+            writer.close();
+        } catch (Exception e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+    }
+
+    // use ObjectOutputStream to write object
+    public void testWriteObject(Foo foo) {
+        FileOutputStream fos;
+        try {
+            fos = new FileOutputStream(fileName3);
+            ObjectOutputStream writer = new ObjectOutputStream(fos);
+            writer.writeObject(foo);
+            writer.close();
+        } catch (Exception e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+
+    }
+
+    // use CSVWriter to write CSV data
+    public void testWriteCSVReport(Foo[] array) {
+        try {
+            CSVWriter writer = new CSVWriter(new FileWriter(fileName4, true), ',');
+            int len = array.length;
+            for (int i = 0; i < len; i++) {
+                writer.writeNext(array[i].toStringArray());
+            }
+            writer.close();
+        } catch (IOException e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+    }
+    
+    
+    //=============== read methods ======
+    // use DataInputStream
+    public double testReadDouble() {
+        DataInputStream stream;
+        double result = 0;
+        try {
+            FileInputStream fis = new FileInputStream(fileName1);
+            stream = new DataInputStream(new BufferedInputStream(fis));
+            result = stream.readDouble();
+            stream.close();
+        } catch (Exception e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+        return result;
+    }
+
+    // use RandomAccessFile to read data from specific position in the file
+    public int testReadFromPosition(long position) {
+        int result = 0;
+        try {
+            RandomAccessFile reader = new RandomAccessFile(fileName2, "r");
+            reader.seek(position);
+            result = reader.readInt();
+            reader.close();
+        } catch (Exception e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+        return result;
+    }
+
+    // use ObjectInputStream to read object
+    public Foo testReadObject() {
+        FileInputStream fis;
+        Foo result = null;
+        try {
+            fis = new FileInputStream(fileName3);
+            ObjectInputStream reader = new ObjectInputStream(fis);
+            result = (Foo) reader.readObject();
+            reader.close();
+        } catch (Exception e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+        return result;
+    }
+
+    // use CSVReader to read CSV data
+    public Foo[] testReadCSVReport() {
+        CSVReader reader;
+        Foo[] result = null;
+        try {
+            reader = new CSVReader(new FileReader(fileName4));
+            List list = reader.readAll();
+            int size = list.size();
+            result = new Foo[size];
+            Foo temp;
+            String[] currentItem;
+            for (int i = 0; i < size; i++) {
+                temp = new Foo();
+                currentItem = (String[]) list.get(i);
+                temp.setId(Long.parseLong(currentItem[0]));
+                temp.setName(currentItem[1]);
+                result[i] = temp;
+            }
+            reader.close();
+        } catch (Exception e) {
+            System.out.println(e.getLocalizedMessage());
+        }
+        return result;
+    }
+
+
+    
+}
