Create a chat application using either TCP or UDP protocol code example

Example: Create a chat application using either TCP or UDP protocol

//Client
import java.io.*;
import java.net.*;
public class GossipClient
{
  public static void main(String[] args) throws Exception
  {
     Socket sock = new Socket("127.0.0.1", 3000);
                               // reading from keyboard (keyRead object)
     BufferedReader keyRead = new BufferedReader(new InputStreamReader(System.in));
                              // sending to client (pwrite object)
     OutputStream ostream = sock.getOutputStream(); 
     PrintWriter pwrite = new PrintWriter(ostream, true);

                              // receiving from server ( receiveRead  object)
     InputStream istream = sock.getInputStream();
     BufferedReader receiveRead = new BufferedReader(new InputStreamReader(istream));

     System.out.println("Start the chitchat, type and press Enter key");

     String receiveMessage, sendMessage;               
     while(true)
     {
        sendMessage = keyRead.readLine();  // keyboard reading
        pwrite.println(sendMessage);       // sending to server
        pwrite.flush();                    // flush the data
        if((receiveMessage = receiveRead.readLine()) != null) //receive from server
        {
            System.out.println(receiveMessage); // displaying at DOS prompt
        }         
      }               
    }                    
}             

//Server
import java.io.*;
import java.net.*;
public class GossipServer
{
  public static void main(String[] args) throws Exception
  {
      ServerSocket sersock = new ServerSocket(3000);
      System.out.println("Server  ready for chatting");
      Socket sock = sersock.accept( );                          
                              // reading from keyboard (keyRead object)
      BufferedReader keyRead = new BufferedReader(new InputStreamReader(System.in));
	                      // sending to client (pwrite object)
      OutputStream ostream = sock.getOutputStream(); 
      PrintWriter pwrite = new PrintWriter(ostream, true);

                              // receiving from server ( receiveRead  object)
      InputStream istream = sock.getInputStream();
      BufferedReader receiveRead = new BufferedReader(new InputStreamReader(istream));

      String receiveMessage, sendMessage;               
      while(true)
      {
        if((receiveMessage = receiveRead.readLine()) != null)  
        {
           System.out.println(receiveMessage);         
        }         
        sendMessage = keyRead.readLine(); 
        pwrite.println(sendMessage);             
        pwrite.flush();
      }               
    }                    
}