【Java网络编程】基于 UDP 的聊天通信

使用 udp 协议，写一个基于命令行的聊天软件；客户端跟服务端分别在命令行启动之后，客户端和服务器端可以互相发送数据。

代码实现如下：

一、创建线程 sendThread 和 receiveThread

 package com.fhcq.chat;

 //双工的聊天程序
 //可以发送数据，同时也可以等待接收数据
 //需要使用多线程来实现

 public class QICQDemo {

     public static void main(String[] args) {
         // TODO Auto-generated method stub

         Send send = new Send();
         Receive receive = new Receive();

         Thread sendThread = new Thread(send);
         Thread receiveThread = new Thread(receive);

         sendThread.start();
         receiveThread.start();
     }
 }

二、利用线程 sendThread 实现信息的发送

 package com.fhcq.chat;

 import java.io.IOException;
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.InetAddress;
 import java.net.SocketException;
 import java.net.UnknownHostException;
 import java.util.Scanner;

 public class Send implements Runnable {

     @Override
     public void run() {
         // TODO Auto-generated method stub

         try {
             DatagramSocket datagramSocket = new DatagramSocket();
             InetAddress inetAddress = InetAddress.getByName("congkick");
             Scanner scanner = new Scanner(System.in);
             while(true){
                 // 阻塞
                 String nextLine = scanner.nextLine();
               byte[] bytes = nextLine.getBytes();
               DatagramPacket datagramPacket = new DatagramPacket
                      (bytes,bytes.length,inetAddress,10019);
                 datagramSocket.send(datagramPacket);
                 if (nextLine.equals("")) {
                     break;
                 }
             }
         } catch (SocketException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } catch (UnknownHostException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }
 }

三、利用线程 receiveThread 实现信息的接收

 package com.fhcq.chat;

 import java.io.IOException;
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.SocketException;

 public class Receive implements Runnable {

     @Override
     public void run() {
         // TODO Auto-generated method stub

         // 新建datagramSocket
         try {
             DatagramSocket datagramSocket = new DatagramSocket(10010);
             byte[] buf = new byte[1024];
             // 阻塞式方法
             DatagramPacket datagramPacket = new DatagramPacket(buf, 1024);
             while(true){
                 datagramSocket.receive(datagramPacket);
                 byte[] data = datagramPacket.getData();
                 int length = datagramPacket.getLength();
                 String string = new String(data,0,length);
                 System.out.println(string);
                 if (string.equals("")) {
                     break;
                 }
             }
         } catch (SocketException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }
 }