JAVA NIO入门实例
基本概念：参考http://zhangshixi.iteye.com/blog/679959作者的系列文章即可
NIO因为其高效性，成为了服务端的首选，大大提高了服务端的响应效率。
我自己读完作者的文章，写了一个简单的DEMO
服务端：
package com.liuc.io;import java.io.IOException;import java.net.InetSocketAddress;import java.nio.ByteBuffer;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.ServerSocketChannel;import java.nio.channels.SocketChannel;import java.nio.charset.Charset;import java.util.Iterator;import java.util.Set;import org.apache.log4j.Logger;public class NIOServer extends Thread {private Logger log=Logger.getLogger(NIOServer.class);private boolean stop=false;private String ip="localhost";private int port=9999;private Selector selector;private ByteBuffer buffer=ByteBuffer.allocate(1024);private Charset gbkCharset = Charset.forName( "GB2312" ); public NIOServer() {try {selector=Selector.open();ServerSocketChannel ssc=ServerSocketChannel.open();InetSocketAddress address=new InetSocketAddress(ip, port);//ServerSocket绑定IPssc.socket().bind(address);//设置为非阻塞模式ssc.configureBlocking(false);//向选择器注册ssc.register(selector,SelectionKey.OP_ACCEPT);System.out.println("Listen to port:"+port);} catch (IOException e) {log.error(e);}}@Overridepublic void run() {System.out.println("deal with request");while(!stop){String content="HelloWorld";try {int numKeys = selector.select();Set<SelectionKey> selectionKeys=selector.selectedKeys();Iterator<SelectionKey> iterator=selectionKeys.iterator();while (iterator.hasNext()) { SelectionKey key = iterator.next(); iterator.remove(); dealRequest(key,content);}} catch (IOException e) {log.equals(e);}}}private void dealRequest(SelectionKey key,String contentToSend) {try { StringBuffer clientContent=new StringBuffer(); if(key.isAcceptable()){//测试此键的通道是否已准备好接受新的套接字连接。 ServerSocketChannel ssc=(ServerSocketChannel) key.channel(); SocketChannel sc=ssc.accept(); sc.configureBlocking(false); sc.register(selector, SelectionKey. OP_READ); }else if(key.isReadable()) {//测试此键的通道是否已准备好进行读取。 SocketChannel sc=(SocketChannel) key.channel(); while(true){//读取全部数据 buffer.clear(); int r=sc.read(buffer); buffer.flip(); byte[] temp=new byte[r]; if (r<=0) {break; } clientContent.append(gbkCharset.decode(buffer).toString()); } //获取全部的数据 String content=clientContent.toString(); String[] info=content.split(",");//用户名密码验证 System.out.println("客户端的验证请求为:"+content); sc.register(selector, SelectionKey.OP_WRITE); }else if(key.isWritable()){//测试此键的通道是否已准备好进行写入System.out.println("要发送的消息为"+contentToSend);buffer.clear();buffer.put(contentToSend.getBytes());buffer.flip();SocketChannel sc = (SocketChannel)key.channel();sc.write(buffer);buffer.flip();//发送完信息后关闭连接key.cancel(); sc.close();}} catch (IOException e) {System.out.println(e);//客户端断开连接，所以从Selector中取消注册 key.cancel();if(key.channel() != null)try {key.channel().close();log.debug("the client socket is closed!");//System.out.println("the client socket is closed!");} catch (IOException e1) {e1.printStackTrace();}}}public static void main(String[] args){new NIOServer().start();}}package com.liuc.io;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.Socket;import java.net.UnknownHostException;public class NIOClient {/** * @param args */public static void main(String[] args) {Socket socket=null;OutputStream outputStream=null;InputStream inputStream=null;try {socket=new Socket("localhost", 9999);outputStream=socket.getOutputStream();String sendContent="HelloWorld";outputStream.write(sendContent.getBytes());outputStream.flush();inputStream=socket.getInputStream();byte[] bytes=new byte[1024];int n=inputStream.read(bytes);System.out.println(new String(bytes));} catch (UnknownHostException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}finally{try {if(inputStream!=null){inputStream.close();}if (outputStream!=null) {outputStream.close();}if (socket!=null) {socket.close();}} catch (IOException e) {e.printStackTrace();}}}}