MULTICAST IN NETWORK PROGRAMMING

receiver.java
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.util.Arrays;

// Server side 
public class receiver
{
 public static void main(String[] args) throws IOException
 {
  InetAddress inetRemoteAddr = InetAddress.getByName("224.0.0.5");

  DatagramPacket recvPack = new DatagramPacket(new byte[1024], 1024);

MulticastSocket server = new MulticastSocket(8888);

 // you must join the multicast group ;
   
  server.joinGroup(inetRemoteAddr);

  System.out.println("---------------------------------");
  System.out.println("Server current start......");
  System.out.println("---------------------------------");

  while (true)
  {
   server.receive(recvPack);

   byte[] recvByte = Arrays.copyOfRange(recvPack.getData(), 0,
     recvPack.getLength());

   System.out.println("Server receive msg:" + new String(recvByte));
  }

 }
}

sender.java
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;

// Client 
public class sender
{
 public static void main(String[] args) throws IOException
 {
  int port = 8888;
  byte[] msg = "Connection successfully!!!".getBytes();

  InetAddress inetRemoteAddr = InetAddress.getByName("224.0.0.5");

     try ( // MulticastSocket
             MulticastSocket client = new MulticastSocket()) {
         DatagramPacket sendPack = new DatagramPacket(msg, msg.length,
                 inetRemoteAddr, port);
        
         client.send(sendPack);
        
         System.out.println("Client send msg complete");
     }

 }
}