Converting Text To and From ByteBuffers

package com.bruceeckel;
 
//: c12:BufferToText.java
//Converting text to and from ByteBuffers
//{Clean: data2.txt}
//From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
//www.BruceEckel.com. See copyright notice in CopyRight.txt.
 
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.Charset;
 
public class BufferToText {
    private static final int BSIZE = 1024;
 
    public static void main(String[] args) throws Exception {
	FileChannel fc = new FileOutputStream("data2.txt").getChannel();
	fc.write(ByteBuffer.wrap("Some text".getBytes()));
	fc.close();
	fc = new FileInputStream("data2.txt").getChannel();
	ByteBuffer buff = ByteBuffer.allocate(BSIZE);
	fc.read(buff);
	buff.flip();
	// Doesn't work:
	System.out.println(buff.asCharBuffer());
	// Decode using this system's default Charset:
	buff.rewind();
	String encoding = System.getProperty("file.encoding");
	System.out.println("Decoded using " + encoding + ": "
		+ Charset.forName(encoding).decode(buff));
	// Or, we could encode with something that will print:
	fc = new FileOutputStream("data2.txt").getChannel();
	fc.write(ByteBuffer.wrap("Some text".getBytes("UTF-16BE")));
	fc.close();
	// Now try reading again:
	fc = new FileInputStream("data2.txt").getChannel();
	buff.clear();
	fc.read(buff);
	buff.flip();
	System.out.println(buff.asCharBuffer());
	// Use a CharBuffer to write through:
	fc = new FileOutputStream("data2.txt").getChannel();
	buff = ByteBuffer.allocate(24); // More than needed
	buff.asCharBuffer().put("Some text");
	fc.write(buff);
	fc.close();
	// Read and display:
	fc = new FileInputStream("data2.txt").getChannel();
	buff.clear();
	fc.read(buff);
	buff.flip();
	System.out.println(buff.asCharBuffer());
    }
}