Use CharBuffer : CharBuffer « File « Java Tutorial

1. Java Tutorial
2. File
3. CharBuffer

import java.nio.ByteBuffer;
import java.nio.CharBuffer;

public class MainClass {

  private static void symmetricScramble(CharBuffer buffer) {
    while (buffer.hasRemaining()) {
      buffer.mark();
      char c1 = buffer.get();
      char c2 = buffer.get();
      buffer.reset();
      buffer.put(c2).put(c1);
    }
  }

  public static void main(String[] args) {
    char[] data = "UsingBuffers".toCharArray();
    ByteBuffer bb = ByteBuffer.allocate(data.length * 2);
    CharBuffer cb = bb.asCharBuffer();
    cb.put(data);
    System.out.println(cb.rewind());
    symmetricScramble(cb);
    System.out.println(cb.rewind());
    symmetricScramble(cb);
    System.out.println(cb.rewind());
  }
}
/*
*/

UsingBuffers
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UsingBuffers