UDP 多播 Java

时间:2021-07-17 20:18:32

1、服务端

public class UdpMulticastServer {

    /**
* @param args
*/
public static void main(String[] args) { // TODO Auto-generated method stub
// 接受组播和发送组播的数据报服务都要把组播地址添加进来
String host = "225.0.0.1";// 多播地址
int port = 9998;
int length = 1024;
byte[] buf = new byte[length];
MulticastSocket ms = null;
DatagramPacket dp = null;
try {
ms = new MulticastSocket(port);
dp = new DatagramPacket(buf, length); // 加入多播地址
InetAddress group = InetAddress.getByName(host);
ms.joinGroup(group); System.out.println("监听多播端口打开:");
while (true) {
ms.receive(dp);
int i;
StringBuffer sbuf = new StringBuffer();
for (i = 0; i < 1024; i++) {
if (buf[i] == 0) {
break;
}
sbuf.append((char) buf[i]);
}
System.out.println("收到多播消息:" + sbuf.toString());
try {
Thread.sleep(1000);
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} }
catch (IOException e) {
e.printStackTrace();
}
}
}

2、客户端

public class UdpMulticastClient {

    /**
* @param args
*/
public static void main(String[] args) { // TODO Auto-generated method stub
String host = "225.0.0.1";// 多播地址
int port = 9998;
String message = "test-multicastSocket";
try {
InetAddress group = InetAddress.getByName(host);
MulticastSocket s = new MulticastSocket();
// 加入多播组
s.joinGroup(group);
DatagramPacket dp = new DatagramPacket(message.getBytes(),
message.length(), group, port);
while (true) {
s.send(dp);
try {
Thread.sleep(1000);
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
catch (UnknownHostException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
}
}