Java - CharArrayWriter reset() method

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Description

The Java CharArrayWriter reset() method is used to clear the current contents of the writer and reset the buffer, allowing it to be reused without creating a new instance.

Declaration

Following is the declaration for java.io.CharArrayWriter.reset() method −

 public void reset() 

Parameters

NA

Return Value

This method does not return any value.

Exception

NA

Example - Using CharArrayWriter reset() method

The following example shows the usage of Java CharArrayWriter reset() method.

CharArrayWriterDemo.java

 package com.tutorialspoint; import java.io.CharArrayWriter; public class CharArrayWriterDemo { public static void main(String[] args) { CharArrayWriter chw = null; try { // create character array writer chw = new CharArrayWriter(); // declare character sequence CharSequence csq = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; // append character sequence to the writer chw.append(csq); System.out.println("Before Reset:"); // print character sequence System.out.println(csq); // invoke reset() chw.reset(); System.out.println("Reset is invoked"); csq = "1234567890"; chw.append(csq); System.out.println("After reset:"); // print character sequence System.out.println(chw.toString()); } catch(Exception e) { // for any error e.printStackTrace(); } finally { // releases all system resources from writer if(chw!=null) chw.close(); } } } 

Output

Let us compile and run the above program, this will produce the following result −

 Before Reset: ABCDEFGHIJKLMNOPQRSTUVWXYZ Reset is invoked After reset: 1234567890 

Example - Using reset() to Clear the Buffer

The following example shows the usage of Java CharArrayWriter reset() method. In this example, we write some data to a CharArrayWriter, display its contents, then reset it and write new data.

CharArrayWriterDemo.java

 package com.tutorialspoint; import java.io.CharArrayWriter; import java.io.IOException; public class CharArrayWriterDemo { public static void main(String[] args) { try { // Creating CharArrayWriter instance CharArrayWriter writer = new CharArrayWriter(); // Writing data to writer writer.write("Hello, World!"); System.out.println("Before reset: " + writer.toString()); // Resetting the writer writer.reset(); // Writing new data after reset writer.write("New Data"); System.out.println("After reset: " + writer.toString()); // Closing the writer (optional) writer.close(); } catch (IOException e) { e.printStackTrace(); } } } 

Output

Let us compile and run the above program, this will produce the following result −

 Before reset: Hello, World! After reset: New Data 

Explanation

• A CharArrayWriter is created.

• The string "Hello, World!" is written into the buffer.

• The buffer is printed to confirm it holds the expected data.

• The reset() method is called, clearing the buffer.

• A new string "New Data" is written to the buffer.

• The buffer is printed again, showing only the new data.

Example - Using reset() in a Loop for Reuse

The following example shows the usage of Java CharArrayWriter reset() method. In this example, we demonstrate reusing the same CharArrayWriter multiple times.

CharArrayWriterDemo.java

 package com.tutorialspoint; import java.io.CharArrayWriter; import java.io.IOException; public class CharArrayWriterDemo { public static void main(String[] args) { try { // Creating CharArrayWriter instance CharArrayWriter writer = new CharArrayWriter(); // Writing and resetting multiple times for (int i = 1; i <= 3; i++) { writer.write("Iteration " + i); System.out.println("Iteration " + i + " Output: " + writer.toString()); // Reset buffer after each iteration writer.reset(); } // Closing the writer (optional) writer.close(); } catch (IOException e) { e.printStackTrace(); } } } 

Output

Let us compile and run the above program, this will produce the following result −

 Iteration 1 Output: Iteration 1 Iteration 2 Output: Iteration 2 Iteration 3 Output: Iteration 3 

Explanation

• A CharArrayWriter is created once.

• Inside a loop, "Iteration X" is written to the buffer and printed.

• The reset() method is called to clear the buffer for the next iteration.

• This allows the same CharArrayWriter to be reused multiple times without creating a new instance.