//***************** Multicast Time Server ***************************
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.net.DatagramPacket;
import java.util.Date;
import java.io.IOException;

public class TimeServerMC {
    public static void main(String[ ] args) {
       try {
           // Join group at network address.
           InetAddress t_group = InetAddress.getByName(addr);
           MulticastSocket mcs = new MulticastSocket(port);
           mcs.joinGroup(t_group);
    
           DatagramPacket t_packet = null;
    
           // Multicast the time every 10 seconds.
            while (true) {
               byte[ ] t_bytes = 
                  new Date().toString().getBytes();
               t_packet = new DatagramPacket(t_bytes, 
                               t_bytes.length, t_group, port);
               mcs.send(t_packet);
               Thread.sleep(winks);
            }
        }
       catch(IOException e) { System.err.println(e); }
       catch(InterruptedException e) { System.err.println(e); }
    }
    private static final int port = 9977;
    private static final String addr = "228.1.2.3";
    private static final int winks = 10000; // milliseconds
}