UDP实现多人聊天

发送端

package com.zy.exercise;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;

public class send1 {

    public static void main(String[] args) throws Exception {
        DatagramSocket datagramSocket = new DatagramSocket();
        InetAddress byName = InetAddress.getByName("127.0.0.1");//如果别的主机要测试此处ip应该为192.168.219.61，即服务器的ip
        System.out.println("欢迎来到多人聊天室");
        Scanner scanner = new Scanner(System.in);
        String username=scanner.nextLine();
        while(true){
        System.out.println("请输入:");
        String str=scanner.nextLine();
        str=username+"说:"+str;
//        System.out.println(str);
        byte b[]=str.getBytes();
        DatagramPacket datagramPacket = new DatagramPacket(b, b.length, byName, 8888);
        datagramSocket.send(datagramPacket);
        if(str.equals("拜拜"))
        {
            System.out.println("退出");
            break;
        }
        }
        datagramSocket.close();

    }

}

服务器端(分发个多个主机)

package com.zy.exercise;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;

public class server {
    //分发给该段网络的所有服务器

    public static void main(String[] args) throws Exception {
        DatagramSocket datagramSocket = new DatagramSocket(8888);
        byte b[]=new byte[1024];
        while(true){
        DatagramPacket datagramPacket = new DatagramPacket(b, b.length);
        datagramSocket.receive(datagramPacket);
        System.out.println(new String(b));
        for (int i = 1; i < 100; i++) {
            DatagramSocket datagramSocket2 = new DatagramSocket();
            InetAddress byName = InetAddress.getByName("192.168.219."+i);
            DatagramPacket datagramPacket2 = new DatagramPacket(b, b.length, byName, 10086);
            datagramSocket2.send(datagramPacket2);

        }

        }
//        datagramSocket.close();

    }

}

接收端

package com.zy.exercise;

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

public class receive1 {

    public static void main(String[] args) throws Exception {
        System.out.println("xxxx聊天群");
        DatagramSocket datagramSocket = new DatagramSocket(10086);

        byte b[]=new byte[1024];
        while(true){
        DatagramPacket datagramPacket = new DatagramPacket(b, b.length);

        datagramSocket.receive(datagramPacket);
        System.out.println(new String(b));
        }

    }

}

结果