即时通信 (广播)

package Test;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.util.Scanner;


public class GuangboSrc {

    /**
     * @param args
     * @throws IOException 
     */
    public static void main(String[] args) throws IOException {
//        创建广播地址
        InetAddress ip=InetAddress.getByName("230.0.0.1");
//        将创建的广播加入到广播组中

        MulticastSocket multicastSocket=new MulticastSocket(55555);
        multicastSocket.joinGroup(ip);
//        创建广播的数据包
        System.out.println("请输入要广播的内容：");
        Scanner scan=new Scanner(System.in);
        String str=scan.next();
        byte[]b=str.getBytes();
        DatagramPacket pancket =new DatagramPacket(b, b.length, ip,55555);
//        发送广播
        multicastSocket.send(pancket);
    }

}

package Test;

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

public class GuanagboDes {
//    接受广播
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
//        广播地址
        InetAddress ip=InetAddress.getByName("230.0.0.1");
//        将广播地址加入到广播组中
        MulticastSocket multicastSocket=new MulticastSocket(55555);
        multicastSocket.joinGroup(ip);
        
//        接收数据报
        byte[]b=new byte[1024];
        DatagramPacket packet =new DatagramPacket(b,b.length);
//        接受广播
        multicastSocket.receive(packet);
//        展示广播内容
        String str=new String(packet.getData(),0,packet.getLength());
        System.out.println("接受到的广播信息是："+str);
        
        
    }

}