08 UDP

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

public class udpBaseServer
{
  public static void main(String[] args) throws IOException
  {
    // Step 1 : Create a socket to listen at port 1234
    DatagramSocket ds = new DatagramSocket(1234);
    byte[] receive = new byte[65535];

    DatagramPacket DpReceive = null;
    while (true)
    {

      // Step 2 : create a DatgramPacket to receive the data.
      DpReceive = new DatagramPacket(receive, receive.length);

      // Step 3 : revieve the data in byte buffer.
      ds.receive(DpReceive);

      System.out.println("Client:-" + data(receive));

      // Exit the server if the client sends "bye"
      if (data(receive).toString().equals("bye"))
      {
        System.out.println("Client sent bye.....EXITING");
        break;
      }

      // Clear the buffer after every message.
      receive = new byte[65535];
    }
  }

  // A utility method to convert the byte array data into a string representation.
  public static StringBuilder data(byte[] a)
  {
    if (a == null)
      return null;
    StringBuilder ret = new StringBuilder();
    int i = 0;
    while (a[i] != 0)
    {
      ret.append((char) a[i]);
      i++;
    }
    return ret;
  }
}

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

public class BaseClient
{
  public static void main(String args[]) throws IOException
  {
    Scanner sc = new Scanner(System.in);

    // Step 1:Create the socket object for carrying the data.
    DatagramSocket ds = new DatagramSocket();

    InetAddress ip = InetAddress.getLocalHost();
    byte buf[] = null;

    // loop while user not enters "bye"
    while (true)
    {
      String inp = sc.nextLine();

      // convert the String input into the byte array.
      buf = inp.getBytes();

      // Step 2 : Create the datagramPacket for sending the data.
      DatagramPacket DpSend = new DatagramPacket(buf, buf.length, ip, 1234);

      // Step 3 : invoke the send call to actually send the data.
      ds.send(DpSend);

      // break the loop if user enters "bye"
      if (inp.equals("bye"))
        break;
    }
  }
}