【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("886")) {
                    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("886")) {
                    break;
                }
            }
        } catch (SocketException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}