Client.java

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

public class Client {
        public Socket socket;
        private BufferedReader bufferedReader;
        private BufferedWriter bufferedWriter;
        private String clientUsername;
        
        public Client(Socket socket, String clientUsername){
            try{
                this.socket = socket;
                this.bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                this.bufferedWriter = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
                this.clientUsername = clientUsername;
            }catch(Exception e){
                closeEverything(socket, bufferedReader, bufferedWriter);
            }
        }
        public void sendMessage(){
            try{
                bufferedWriter.write(clientUsername);
                bufferedWriter.newLine();
                bufferedWriter.flush();
                
                Scanner scanner = new Scanner(System.in);
                while(socket.isConnected()){
                    String message = scanner.nextLine();
                    bufferedWriter.write(clientUsername + ':' + message);
                    bufferedWriter.newLine();
                    bufferedWriter.flush();
                }
            }catch (Exception e){
                closeEverything(socket, bufferedReader, bufferedWriter);
            }
        }
    public void listenForMessages(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                String message;
                while (socket.isConnected()){
                    try{
                        message = bufferedReader.readLine();
                        System.out.println(message);
                    } catch (IOException e) {
                        closeEverything(socket, bufferedReader, bufferedWriter);
                    }
                }
            }
        }).start();
    }
    public void closeEverything(Socket socket, BufferedReader bufferedReader, BufferedWriter bufferedWriter){
        try{
            if (bufferedReader != null) {
                bufferedReader.close();
            }
            if (bufferedWriter != null) {
                bufferedWriter.close();
            }
            if(socket != null){
                socket.close();
            }
        } catch(IOException e){
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args) throws IOException {
            Scanner scanner = new Scanner(System.in);
            System.out.println("Enter your username: ");
            String username = scanner.nextLine();
            Socket socket = new Socket("localhost", 6013);
            Client client = new Client(socket, username);
            client.listenForMessages();
            client.sendMessage();
            
        try {
            Socket sock = new Socket("127.0.0.1", 6013);
            OutputStream out = sock.getOutputStream();
            PrintWriter pout = new PrintWriter(out, true);

            // Read the input from the user
            BufferedReader userInput = new BufferedReader(new InputStreamReader(System.in));
            System.out.print("Enter input: ");
            String input = userInput.readLine();

            // Send the input to the server
            pout.println(input);

            // Read the response from the server
            InputStream in = sock.getInputStream();
            BufferedReader bin = new BufferedReader(new InputStreamReader(in));
            String response = bin.readLine();
            String result = response.replaceAll(".%", ".\n");
            System.out.println("Server response: \n" + result);

            sock.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}