网上资料大把，但要写写代码，我这个年纪的人才有一点点记忆了。。

参考URL：

http://blog.csdn.net/wuxianglong/article/details/6612282

package com.cg.io;import java.io.*;import java.nio.*;import java.nio.channels.*;public class TestIntBuffer {  static private final byte message[] = {83, 111, 109, 101, 32, 98, 98};  static private String fileName = "d:\\hehehe\\test.txt";  public static void main(String[] args) throws Exception {    FileOutputStream fout = new FileOutputStream(fileName);    FileChannel fc = fout.getChannel();    ByteBuffer byteBuffer = ByteBuffer.allocate(1024);    output("初始化", byteBuffer);    for (int i=0; i
     
       0) {      byte b = byteBuffer.get();      System.out.print(((char)b));    }    output("调用getChannel()", byteBuffer);    byteBuffer.clear();    output("调用clear()", byteBuffer);    fin.close();    IntBuffer intBuffer = IntBuffer.allocate(8);    for (int i=0; i < intBuffer.capacity(); ++i) {      int j = 2 * (i + 1);      intBuffer.put(j);    }    intBuffer.flip();    while (intBuffer.hasRemaining()) {      int j = intBuffer.get();      System.out.print(j + " ");    }  }  public static void output(String step, Buffer buffer){    System.out.println(step + " : ");    System.out.println("capacity: " + buffer.capacity() + ", ");    System.out.println("position: " + buffer.position() + ", ");    System.out.println("limit: " + buffer.limit() + ", ");    System.out.println();  }}