Modify TestWriter

Adding some test methods

core-java/src/test/java/org/baeldung/java/io/TestWriter.java

@@ -1,30 +1,32 @@
 package test;
 
-import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
+import java.io.File;
 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.PrintWriter;
 import java.io.RandomAccessFile;
-import java.util.List;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileLock;
 
-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 fileName = "test.txt";
     private String fileName1 = "test1.txt";
     private String fileName2 = "test2.txt";
     private String fileName3 = "test3.txt";
-    private String fileName4 = "test4.csv";
+    private String fileName4 = "test4.txt";
+    private String fileName5 = "test5.txt";
 
     public TestWriter(String name) {
         super(name);
@@ -37,11 +39,28 @@ public class TestWriter extends TestCase {
     protected void tearDown() throws Exception {
         super.tearDown();
     }
+    
+    public void testWriteFormattedStringUsingPrintWriter() throws IOException{
+        FileWriter fileWriter = new FileWriter(fileName);
+        PrintWriter printWriter = new PrintWriter(fileWriter);
+        printWriter.printf("Product name is %s and its price is %d $","iPhone",1000);
+        printWriter.close();
+    }
 
-    public void testWriteDouble_thenReadIt_shouldBeTheSame() {
+    public void testWriteStringWithDataOutputStream_thenReadIt_shouldBeTheSame() throws IOException {
-        double value = 2.5;
+        String value = "Hello";
-        testWriteDouble(value);
+        FileOutputStream fos = new FileOutputStream(fileName1);
-        assertEquals(value, testReadDouble(), 0.0000001);
+        DataOutputStream outStream = new DataOutputStream(new BufferedOutputStream(fos));
+        outStream.writeUTF(value);
+        outStream.close();
+        
+        String result;
+        FileInputStream fis = new FileInputStream(fileName1);
+        DataInputStream reader = new DataInputStream(fis);
+        result = reader.readUTF();
+        reader.close();
+        
+        assertEquals(value, result);
     }
 
     public void testWriteToPosition_editValueIfSpecificPos_shouldChange() {
@@ -53,39 +72,62 @@ public class TestWriter extends TestCase {
         assertEquals(data2, testReadFromPosition(4));
     }
 
-    public void testWriteObject_thenReadIt_instanceVariableValuesShouldBeTheSame() {
+    public void testWriteObject_thenReadIt_instanceVariableValuesShouldBeTheSame() throws Exception {
         Foo foo = new Foo(1, "John");
-        testWriteObject(foo);
+        FileOutputStream fos = new FileOutputStream(fileName3);
-        Foo read = testReadObject();
+        ObjectOutputStream writer = new ObjectOutputStream(fos);
-        assertEquals(foo.getId(), read.getId());
+        writer.writeObject(foo);
-        assertEquals(foo.getName(), read.getName());
+        writer.close();
+        Foo result = null;
+
+        FileInputStream fis = new FileInputStream(fileName3);
+        ObjectInputStream reader = new ObjectInputStream(fis);
+        result = (Foo) reader.readObject();
+        reader.close();
+
+        assertEquals(foo.getId(), result.getId());
+        assertEquals(foo.getName(), result.getName());
     }
 
-    public void testWriteCSVReport_thenReadAllData_shouldBeTheSame() {
+    public void testFileLock() throws IOException {
-        Foo[] arr = new Foo[3];
+        RandomAccessFile stream = new RandomAccessFile(fileName4, "rw");
-        arr[0] = new Foo(1, "John");
+        FileChannel channel = stream.getChannel();
-        arr[1] = new Foo(2, "Adam");
+
-        arr[2] = new Foo(3, "Jane");
+        FileLock lock = channel.tryLock();
-        testWriteCSVReport(arr);
+        stream.writeChars("test lock");
-        Foo[] read = testReadCSVReport();
+        lock.release();
-        assertEquals(arr[0].getId(), read[0].getId());
+        
-        assertEquals(arr[2].getName(), read[2].getName());
+        stream.close();
-        assertEquals(arr[1].getId(), read[1].getId());
+        channel.close();
-    }
-//================= 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());
-        }
     }
 
+    
+    public void testCreateFile_thenCheckIfItExists_thenDeleteAndCheckIfExist() throws IOException{
+        File file = new File("test_create.txt");
+        file.createNewFile();
+        assertTrue(file.exists());
+        file.delete();
+        assertFalse(file.exists());
+    }
+    
+    public void testWriteStringUsingFileChannel() throws IOException{
+        RandomAccessFile stream = new RandomAccessFile(fileName5, "rw");
+        FileChannel channel = stream.getChannel();
+        String value = "Hello";
+        byte[] strBytes = value.getBytes();
+        ByteBuffer buffer = ByteBuffer.allocate(strBytes.length);
+        buffer.put(strBytes);
+        buffer.flip();
+        channel.write(buffer);        
+        stream.close();
+        channel.close();
+        
+        RandomAccessFile reader = new RandomAccessFile(fileName5, "r");
+        assertEquals(value , reader.readLine());
+        reader.close();
+        
+    }
+    
     // use RandomAccessFile to write data at specific position in the file
     public void testWriteToPosition(int data, long position) {
         try {
@@ -98,50 +140,7 @@ public class TestWriter extends TestCase {
         }
     }
 
-    // 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) {
@@ -157,46 +156,8 @@ public class TestWriter extends TestCase {
         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;
-    }
-
 
     
 }