ntddpracticals

//UDPCLIENT


import java.io.*;
import java.net.*;
public class client
{
 public static void main(String args[])
 {
  try
  {
   DatagramSocket socket=new DatagramSocket();
   byte [] buff=new byte[1024];
   InetAddress address=InetAddress.getByName("localhost");
   System.out.println("Trying...to connect to the server.");
   while(true)
   {
    System.out.println("Enter data");
    BufferedReader buff_data=new BufferedReader(new InputStreamReader(System.in));
    String user_data=buff_data.readLine();
    buff=user_data.getBytes();
    DatagramPacket packet=new DatagramPacket(buff,buff.length,address,4455);
    socket.send(packet);
   }
  }
  catch(UnknownHostException unknown_host)
  {
   System.out.println("Unknown host..");
   unknown_host.printStackTrace();
  }
  catch(SocketException socket_error)
  {
   System.out.println("Some socket error has occured.");
   socket_error.printStackTrace();
  }
  catch(IOException input_error)
  {
   System.out.println("Some input error has occured.");
   input_error.printStackTrace();
  }
 }
}

//UDPSERVER

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.io.IOException;
import java.net.SocketException;
public class server
{
 public static void main(String args[])
 {
  new server().chatting();
 }
 public void chatting()
 {
  try
  {
   DatagramSocket socket=new DatagramSocket(4455);
   byte[] buff=new byte[1024];
   while(true)
   {
    DatagramPacket packet=new DatagramPacket(buff,buff.length);
    socket.receive(packet);
    String client_packet=new String(packet.getData(),0,packet.getLength());
    System.out.println("Received a packet from client "+client_packet);
   }
  }
  catch(SocketException socket_error)
  {
   System.out.println("Socket exception has occured.");
   socket_error.printStackTrace();
  }
  catch(IOException input_error)
  {
   System.out.println("Input error has occured.");
   input_error.printStackTrace();
  }
 }
}