import java.io.*;
import java.net.*;

public class MulticastSender {

  public static void main(String[] args) {
  
    InetAddress ia = null;
    int port = 0;
    byte ttl = (byte) 1;
  
    // read the address from the command line
    try {
      ia = InetAddress.getByName(args[0]);
      port = Integer.parseInt(args[1]);
      if (args.length > 2) ttl = (byte) Integer.parseInt(args[2]);
    } catch (NumberFormatException | IndexOutOfBoundsException
        | UnknownHostException ex)  {
      System.err.println(ex);
      System.err.println(
          "Usage: java MulticastSender multicast_address port ttl");
      System.exit(1);
    }
  
    byte[] data = "Here's some multicast data\r\n".getBytes();
    DatagramPacket dp = new DatagramPacket(data, data.length, ia, port);
  
    try (MulticastSocket ms = new MulticastSocket()) {
      ms.setTimeToLive(ttl);
      ms.joinGroup(ia);
      for (int i = 1; i < 10; i++) {
        ms.send(dp);
      }
      ms.leaveGroup(ia);
    } catch (SocketException ex) {
      System.err.println(ex);
    } catch (IOException ex) {
      System.err.println(ex);
    }  
  }
}