[网络协议]UDP组播（2）

public class FileMulticastClient {

    //客户端
    public static void main(String[] args) throws IOException, InterruptedException {

        InetAddress groupAddress = InetAddress.getByName("239.0.0.1");//组播地址
        MulticastSocket receiveSocket = new MulticastSocket(9999);  //创建socket
        receiveSocket.joinGroup(groupAddress); //将创建的socket加入组播组
        byte[] buffer = new byte[1024];
        while(true){
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
            receiveSocket.receive(packet);   //阻塞等待组播
            Thread.sleep(1000);
            String s = new String(packet.getData(), 0, packet.getLength());
            System.out.println(s);
        }
    }
}

//组播服务器
public class FileMulticastServer {
    public static void main(String[] args) throws IOException {

        InetAddress groupAddress = InetAddress.getByName("239.0.0.1");
        MulticastSocket sendSocket = new MulticastSocket(0);//0 就是随机取一个没有使用的端口

        while(true){
            String str = "qweqweqwe";
            byte[] buffer = str.getBytes();
            DatagramPacket datagramPacket = new DatagramPacket(buffer, buffer.length,
                    groupAddress,9999);  //发送到组播地址的包
            sendSocket.send(datagramPacket);
        }
    }
}