Java DatagramSocket .send (DatagramPacket p)

public void send(DatagramPacket p)  throws IOException

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
//from   ww w .  j  ava2 s. com
public class Main {

  public static void main(String[] args) {

    try {
      String data = "data in UDP";
      byte [] buffer = data.getBytes();

      DatagramPacket packet = new DatagramPacket(buffer, buffer.length,
                new InetSocketAddress("localhost", 5002));

      DatagramSocket socket = new DatagramSocket(5003);

      System.out.println("Sending a packet...");
      socket.send(packet);
    }catch(IOException e)
    {
      e.printStackTrace();
    }
  }
}