Java网络编程四 非阻塞通信UDP

转自 http://blog.csdn.net/alangdangjia/article/details/9065845

import java.io.BufferedReader;  

 import java.io.ByteArrayInputStream;  

 import java.io.DataInputStream;  

 import java.io.IOException;  

 import java.io.InputStreamReader;  

 import java.net.DatagramSocket;  

 import java.net.InetSocketAddress;  

 import java.nio.ByteBuffer;  

 import java.nio.channels.DatagramChannel;  

 import java.nio.channels.SelectionKey;  

 import java.nio.channels.Selector;  

 import java.util.Set;  

  

 public class NioUdpServer {  

  

     public static void main(String[] args) {  

         try {  

             Selector selector = Selector.open();  

             DatagramChannel channel = DatagramChannel.open();  

             channel.configureBlocking(false);  

             DatagramSocket socket = channel.socket();  

             socket.bind(new InetSocketAddress(1000));  

             channel.register(selector, SelectionKey.OP_READ);  

               

            ByteBuffer receiveBuffer = ByteBuffer.allocate(1024);  

             final int PACKAGE_SIZE = 10;  

             while(true){  

                 int n = selector.select();  

                 if(n == 0){  

                     continue;  

                 }  

                 Set<SelectionKey> readyKeys = selector.selectedKeys();  

                 for(SelectionKey key : readyKeys){  

                     readyKeys.remove(key);  

                       

                    if(key.isReadable()){  

                         DatagramChannel dc = (DatagramChannel)key.channel();  

                         InetSocketAddress client = (InetSocketAddress)dc.receive(receiveBuffer); //接收来自任意一个Client的数据报  

                         key.interestOps(SelectionKey.OP_READ);  

                           

                        System.out.println("client ----> IP: " + client.getAddress().getHostAddress() + ", port: " + client.getPort());  

                         System.out.println("receiveBuffer.position() = " + receiveBuffer.position());  

                         if(receiveBuffer.position() >= PACKAGE_SIZE){  

                             receiveBuffer.flip();  

                             DataInputStream dis = new DataInputStream(new ByteArrayInputStream(receiveBuffer.array()));  

                             System.out.println(dis.readInt());  

                             BufferedReader d = new BufferedReader(new InputStreamReader(dis));  

                             System.out.println(d.readLine());  

                               

                            receiveBuffer.clear();  

                         }else{  

                             dc.register(selector, SelectionKey.OP_READ);  

                         }  

                     }//if  

                 }  

             }//while  

         } catch (IOException e) {  

             e.printStackTrace();  

         }  

  

     }  

  

 }  



2. 客户端

[java] view
plain copy

import java.net.DatagramPacket;  

import java.net.DatagramSocket;  

import java.net.InetAddress;  

import java.net.UnknownHostException;  

  

public class NioUdpClient extends Thread {  

    private byte[] sendData;  

    private InetAddress serverAddr;  

    private int port;  

    private int dataLen;  

      

    public NioUdpClient(InetAddress ip, int port, byte[] str,int len) {  

        this.serverAddr = ip;  

        this.sendData = str;  

        this.dataLen = len;  

        this.port = port;  

    }  

      

    public static void main(String[] args) {  

  

//      //测试字符串  

        byte[] bys = new byte[256];  

        for(int i = 0; i < 256; i++){  

            bys[i] = (byte) i;  

        }  

        for(int i = 0; i < bys.length; i++){  

            System.out.println(i + "--->" + bys[i]);  

        }  

        while(true){  

            try {  

                new Thread(new NioUdpClient(InetAddress.getLocalHost(), 1000, bys,256)).start();  

            } catch (UnknownHostException e) {  

                // TODO Auto-generated catch block  

                e.printStackTrace();  

            }  

            Thread.currentThread();  

            try {  

                Thread.sleep(200);  

            } catch (InterruptedException e) {  

                // TODO Auto-generated catch block  

                e.printStackTrace();  

            }  

        }  

    }  

      

  

    public void run() {  

          

        try {  

  

            System.out.println("Client: Start connecting\n");  

            DatagramSocket socket = new DatagramSocket();  

  

            DatagramPacket packet = new DatagramPacket(sendData, dataLen, serverAddr, port);  

            System.out.println("Client: Sending "+dataLen+"bytes'" + new String(sendData) + "'\n");  

            socket.send(packet);  

            System.out.println("Client: Message sent\n");  

            System.out.println("Client: Succeed!\n");  

        } catch (Exception e) {  

            System.out.println("Client: Error!\n");  

        }  

    }  

}