Implement chatting using TCP

server

import java.io.*;

import java.net.*;

class TCPServer{

      public static void main(String[] args) throws IOException{

            String clientsentence;

            String capitalizedSentence;

            ServerSocket welcomeSocket = new ServerSocket(6789);

            while(true){

                  Socket connectionSocket = welcomeSocket.accept();

                  DataInputStream inFromClient = new DataInputStream(connectionSocket.getInputStream());

                  DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());

                  clientsentence = inFromClient.readLine();

                        System.out.println("From Client: " + clientsentence);

                  capitalizedSentence = clientsentence.toUpperCase()+'\n';

                  outToClient.writeBytes(capitalizedSentence);

            }

      }

}

 Client

import java.io.*;

import java.net.*;

class TCPClient{

      public static void main(String[] args) throws IOException {

            String sentence;

            String modifiedSentence;

            Socket clientSocket = new Socket("localhost",6789);

            DataInputStream inFromUser = new DataInputStream(System.in);

            DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());

            DataInputStream inFromServer = new DataInputStream(clientSocket.getInputStream());

            sentence=inFromUser.readLine();

            outToServer.writeBytes(sentence+'\n');

            modifiedSentence=inFromServer.readLine();

            System.out.println("From Server : "+modifiedSentence);

            clientSocket.close();                    

      }

}

OUTPUT :

run:

From Client: Hiii From Server