UDP学习之一，UDP的简单例子

UDP学习之一，UDP的简单例子

import  java.net. * ;
import  java.io. * ;
public   class  EchoClient  {
  private String remoteHost="localhost";
  private int remotePort=8000;
  private DatagramSocket socket;

  public EchoClient()throws IOException{
     socket=new DatagramSocket(); //与本地的任意一个UDP端口绑定
  }
  public static void main(String args[])throws IOException{
    new EchoClient().talk();
  }
  public void talk()throws IOException {
    try{
      InetAddress remoteIP=InetAddress.getByName(remoteHost);

      BufferedReader localReader=new BufferedReader(new InputStreamReader(System.in));
      String msg=null;
      while((msg=localReader.readLine())!=null){
        byte[] outputData=msg.getBytes();
        DatagramPacket outputPacket=new DatagramPacket(outputData,
                                    outputData.length,remoteIP,remotePort);
        socket.send(outputPacket);  //给EchoServer发送数据报
        
        DatagramPacket inputPacket=new DatagramPacket(new byte[512],512);
        socket.receive(inputPacket);
        System.out.println(new String(inputPacket.getData(),0,inputPacket.getLength()));  
        if(msg.equals("bye"))
          break;
       }
    }catch(IOException e){
       e.printStackTrace();
    }finally{
       socket.close();
    }
  }
}   



/** */ /****************************************************
 * 作者：孙卫琴                                     *
 * 来源：<<Java网络编程精解>>                       *
 * 技术支持网址：www.javathinker.org                *
 ***************************************************/

import  java.io. * ;
import  java.net. * ;
public   class  EchoServer  {
  private int port=8000;
  private DatagramSocket socket;

  public EchoServer() throws IOException {
    socket=new DatagramSocket(port); //与本地的一个固定端口绑定
    System.out.println("服务器启动");
  }

  public String echo(String msg) {
    return "echo:" + msg;
  }

  public void service() {
    while (true) {
      try {
        DatagramPacket packet=new DatagramPacket(new byte[512],512);
        socket.receive(packet);  //接收来自任意一个EchoClient的数据报
        String msg=new String(packet.getData(),0,packet.getLength());         
        System.out.println(packet.getAddress() + ":" +packet.getPort()
                            +">"+msg);
        
        packet.setData(echo(msg).getBytes());
        socket.send(packet);  //给EchoClient回复一个数据报
      }catch (IOException e) {
         e.printStackTrace();
      }
    }
  }

  public static void main(String args[])throws IOException {
    new EchoServer().service();
  }
}



/** */ /****************************************************
 * 作者：孙卫琴                                     *
 * 来源：<<Java网络编程精解>>                       *
 * 技术支持网址：www.javathinker.org                *
 ***************************************************/

import  java.io.IOException;
import  java.net.DatagramPacket;
import  java.net.DatagramSocket;
import  java.net.InetAddress;
import  java.net.UnknownHostException;

public   class  SendUdpData  {
    private String remoteHost = "localhost";
    private int remotePort = 8000;
    private DatagramSocket socket;

    public SendUdpData() throws IOException {
        socket = new DatagramSocket(); // 与本地的任意一个UDP端口绑定
    }

    public void sendData() {
        try {
            InetAddress remoteIP = InetAddress.getByName(remoteHost);
            byte[] outputData = "Hello!".getBytes();
            DatagramPacket outputPacket = new DatagramPacket(outputData,
                    outputData.length, remoteIP, remotePort);
            socket.send(outputPacket); // 给EchoServer发送数据报
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            socket.close();
        }
    }

    public static void main(String[] args) throws IOException {
        new SendUdpData().sendData();
    }
}