CharBuffer compact() method in Java

The buffer can be compacted using the compact() method in the class java.nio.CharBuffer. This method does not require a parameter and it returns the new compacted CharBuffer with the same content as the original buffer. If the buffer is read-only, then the ReadOnlyBufferException is thrown.

A program that demonstrates this is given as follows −

Example

 Live Demo

import java.nio.*;
import java.util.*;
public class Demo {
   public static void main(String[] args) {
      int n = 5;
      try {
         CharBuffer buffer = CharBuffer.allocate(n);
         buffer.put('A');
         buffer.put('B');
         buffer.put('C');
         System.out.println("The Original CharBuffer is: " + Arrays.toString(buffer.array()));
         System.out.println("The position is: " + buffer.position());
         System.out.println("The limit is: " + buffer.limit());
         CharBuffer bufferCompact = buffer.compact();
         System.out.println("
The Compacted CharBuffer is: " + Arrays.toString(bufferCompact.array()));
         System.out.println("The position is: " + bufferCompact.position());
         System.out.println("The limit is: " + bufferCompact.limit());
      } catch (IllegalArgumentException e) {
         System.out.println("Error!!! IllegalArgumentException");
      } catch (ReadOnlyBufferException e) {
         System.out.println("Error!!! ReadOnlyBufferException");
      }
   }
}

Output

The Original CharBuffer is: [A, B, C, , ]
The position is: 3
The limit is: 5
The Compacted CharBuffer is: [, , C, , ]
The position is: 2
The limit is: 5