Java CharBuffer encode to ByteBuffer

import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;

public class Main {

   public static void main(String[] args) {
      try {/*  w w w  .ja  va 2  s  .co m*/
         String unicodeString = "\u0012\u0023\u1023";
         System.out.printf("Original string: %s\n", unicodeString);
         CharBuffer srcBuffer = CharBuffer.wrap(unicodeString);
         ByteBuffer targetBytes = encodeBuffer("UTF8", srcBuffer);
         printBytes(targetBytes);
         CharBuffer roundtripBuffer = decodeBuffer("UTF8", targetBytes);
         printCharBuffer(roundtripBuffer);

      } catch (CharacterCodingException ex) {
         ex.printStackTrace();
      }
   }

   public static ByteBuffer encodeBuffer(String charsetName, CharBuffer charBuffer) throws CharacterCodingException {
      Charset charset = Charset.forName(charsetName);
      CharsetEncoder encoder = charset.newEncoder();
      ByteBuffer targetBuffer = encoder.encode(charBuffer);
      return targetBuffer;

   }

   public static CharBuffer decodeBuffer(String charsetName, ByteBuffer srcBuffer) throws CharacterCodingException {
      Charset charset = Charset.forName(charsetName);
      CharsetDecoder decoder = charset.newDecoder();
      CharBuffer charBuffer = decoder.decode(srcBuffer);
      return charBuffer;
   }

   private static void printCharBuffer(CharBuffer buff) {
      String str = buff.toString();
      System.out.printf("Roundtrip string: %s\n", str);
   }

   private static void printBytes(ByteBuffer bytes) {
      System.out.print("Bytes: ");
      byte[] byteArray = bytes.array();
      for (byte b : byteArray) {
         if (b == 0)
            break;
         System.out.printf("%2x ", b);
      }
      System.out.printf("\n");
   }
}