udpclient.java

贪食蛇的实现源码

package com.henry.networkings;

import java.io.*;
import java.net.*; 

public class UDPClient { 
    public static void main(String args[]) { 
        UDPClient udpClient = new UDPClient(); 
        try { 
            udpClient.go(); 
        } catch (Exception e) { 
            System.out.println ("Exception occured with socket."); 
            System.out.println (e); 
            System.exit(1); 
        } 
    } 
        
   public void go() throws IOException, UnknownHostException { 
        DatagramSocket datagramSocket=null; 
        DatagramPacket outDataPacket=null; // Datagram packet to the server 

        DatagramPacket inDataPacket=null; // Datagram packet from the server 

        InetAddress serverAddress=null; // Server host address 

        byte[] msg = new byte[100]; // Buffer space.         
  
        // 1.  create datagram socket
        datagramSocket = new DatagramSocket(); 
        System.out.println("!!!!at UDPClient,  local port is: " +datagramSocket.getLocalPort()); 
  
         // Server is running on this same machine for this example. 
         // This method can throw an UnknownHostException. 
        serverAddress = InetAddress.getLocalHost();  //get an object of InetAddress 
        //serverAddress = InetAddress.getByName( serverhostName);


        //2.  Set up packet to send,   sent to the server on port 8000  
        //    to let server know the client's address    
        outDataPacket = new DatagramPacket(msg, 1, serverAddress, 9000); 
  
        //3.   send data packet to server
        datagramSocket.send(outDataPacket); 
  
        //4. Set up a datagram packet to receive server's data. 
        inDataPacket = new DatagramPacket(msg, msg.length); 
  
        //5. Receive data packet from the server 
        datagramSocket.receive(inDataPacket); 
  
        //6.  Parse the data received from the server:  byte[]   ->  String
        String receivedMsg = new String(inDataPacket.getData(), 0, inDataPacket.getLength()); 
 
        System.out.println(receivedMsg); //display  message on screen
  
        //close the socket 
        datagramSocket.close(); 
    } 
  
   
}