Java多播套接字在Windows上什么都没有收到

Question

I need to send and receive in multicast.

This is my Sender:

public static void main(String[] args) {

    MulticastSocket socket = null;
    try {
        socket = new MulticastSocket(3575);
        int n = 1;
        while (n <= 100) {
            byte[] buf = new byte[256];
            // non aspetta la richiesta
            String dString = new Date().toString();
            buf = dString.getBytes();

            // invia il messaggio in broadcast
            InetAddress group = InetAddress.getByName("230.0.0.1");
            DatagramPacket packet = new DatagramPacket(buf, buf.length, group, 3575);
            socket.send(packet);
            System.out.println ("Broadcasting: "+dString);
            Thread.sleep(1000);
            n++;
        }
        socket.close();
    }catch(Exception e) { e.printStackTrace(); socket.close();}

}//main

This is my Receiver:

public static void main(String[] args) throws IOException {

    MulticastSocket socket = new MulticastSocket(3575);
    InetAddress group = InetAddress.getByName("230.0.0.1");
    socket.joinGroup(group);
    DatagramPacket packet;
    for (int i = 0; i < 100; i++) {
        byte[] buf = new byte[256];
        packet = new DatagramPacket(buf, buf.length);
        socket.receive(packet);
        String received = new String(packet.getData()).trim();
        System.out.println("Time: " + received);
    }
    socket.leaveGroup(group);
    socket.close();
}//main

When I run them, the Receiver does not receive anything. I tried on two different PC ( both with Windows) with AntiVirus and firewall disabled. I also tried with different LAN: my router, my phone hotspot. It does not work neither on local machine.

How can I solve the problem? Thanks

Answer 1

I compiled and ran your code on my laptop, with the sender and receiver on the same machine. It works. (Fedora 26 Linux, Java 1.8.0_171)

It seems that the problem is something to do with your networking, not the application code. So, since this not a programming problem, I think you would be better off asking this Question on the ServerFault site ... where they specialize in networking, etcetera.