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
我自己读完作者的文章，写了一个简单的DEMO
服务端：
Java代码  收藏代码

    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IP 
                ssc.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); 
            } 
             
        } 
     
        @Override 
        public 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(); 
        } 
     
    } 
    客户端： 
    <pre class="java" name="code"> 
    </pre> 
    <br>package com.liuc.io; 
    <br> 
    <br>import java.io.IOException; 
    <br>import java.io.InputStream; 
    <br>import java.io.OutputStream; 
    <br>import java.net.Socket; 
    <br>import java.net.UnknownHostException; 
    <br> 
    <br>public class NIOClient { 
    <br> 
    <br>    /**
    <br>     * @param args
    <br>     */ 
    <br>    public static void main(String[] args) { 
    <br>        Socket socket=null; 
    <br>        OutputStream outputStream=null; 
    <br>        InputStream inputStream=null; 
    <br>        try { 
    <br>            socket=new Socket("localhost", 9999); 
    <br>            outputStream=socket.getOutputStream(); 
    <br>            String sendContent="HelloWorld"; 
    <br>            outputStream.write(sendContent.getBytes()); 
    <br>            outputStream.flush(); 
    <br>             
    <br>             
    <br>            inputStream=socket.getInputStream(); 
    <br>            byte[] bytes=new byte[1024]; 
    <br>            int n=inputStream.read(bytes); 
    <br>            System.out.println(new String(bytes)); 
    <br>             
    <br>             
    <br>        } catch (UnknownHostException e) { 
    <br>            e.printStackTrace(); 
    <br>        } catch (IOException e) { 
    <br>            e.printStackTrace(); 
    <br>        }finally{ 
    <br>            try { 
    <br>                    if(inputStream!=null){ 
    <br>                        inputStream.close(); 
    <br>                    } 
    <br>                    if (outputStream!=null) { 
    <br>                        outputStream.close(); 
    <br>                    } 
    <br>                    if (socket!=null) { 
    <br>                        socket.close(); 
    <br>                    } 
    <br>            } catch (IOException e) { 
    <br>                e.printStackTrace(); 
    <br>            } 
    <br>             
    <br>        } 
    <br>         
    <br> 
    <br>    } 
    <br> 
    <br>} 
    <br>