Client.java

import java.io.*;
import java.net.*;
 
public class Client{
    public static void main(String[] args) {
    
        String hostname = "localhost";
        int port = 5555;
 
        Socket clientSocket = null;  
        DataOutputStream out = null;
        BufferedReader in = null;
        
        try {
            clientSocket = new Socket(hostname, port);
            out = new DataOutputStream(clientSocket.getOutputStream());
            in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                
        } catch (UnknownHostException e) {
            System.err.println("Cannot connect");
        } catch (IOException e) {
            System.err.println("IOException");
        }
        
        if (clientSocket == null || out == null || in == null) {
            System.err.println( "Somethisg in wrong. One variable in null." );
            return;
        }
        
        try {
            while (true) {
                System.out.print("Enter an integer: ");
                BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                String keyboardInput = br.readLine();
                out.writeBytes(keyboardInput + "\n" );
                out.flush();
        
                String responseFromServer = in.readLine();
                System.out.println("Server: " + responseFromServer);
                
            }
            
        } catch (UnknownHostException e) {
            System.err.println("Cannot connect");
        } catch (IOException e) {
            System.err.println("IOException");
        } 
    }           
}

Server.java

import java.io.*;
import java.net.*;
import java.util.Scanner;
 
public class Server {
    public static void main(String args[]) {
        int port = 5555;
        Server server = new Server(port);
        server.startServer();
    }
 
    ServerSocket echoserver = null;
    Socket clientSocket = null;
    int numOfConnection = 0;
    int port;
    
    public Server(int port) {
        this.port = port;
    }
 
    public void stopServer() {
        System.out.println( "Server cleaning up." );
        System.exit(0);
    }
 
    public void startServer() {
        try {
            echoserver = new ServerSocket(port);
        }catch (IOException e) {
            System.out.println(e);
        }   
        
        Scanner input = new Scanner(System.in);
        System.out.print("Enter the secret number: ");
        int secret = input.nextInt();
        System.out.println("Secret in "+ secret);
        System.out.println("Let's begin the game!");
 
        while (true) {
            try {
                clientSocket = echoserver.accept();
                numOfConnection ++;
                ServerConnection oneconnection = new ServerConnection(clientSocket, numOfConnection, secret);
                new Thread(oneconnection).start();
            }   
            catch (IOException e) {
                System.out.println(e);
            }
        }
    }
}
 
class ServerConnection implements Runnable {
    BufferedReader in;
    PrintStream out;
    Socket clientSocket;
    Server server;
    int clientcount,secret;
 
    public ServerConnection(Socket clientSocket, int clientcount, int secret) {
        this.clientSocket = clientSocket;
        this.clientcount = clientcount;
        this.server = server;
        this.secret = secret;
        System.out.println( "Player #" + clientcount + " Accepted from " + clientSocket.getRemoteSocketAddress().toString() );
        try {
            in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
            out = new PrintStream(clientSocket.getOutputStream());
        }catch (IOException e) {
            System.out.println(e);
        }
    }
 
    public void run() {
        String readLineFromClient;
        try {
            while (true) {
                readLineFromClient = in.readLine();
                int input = Integer.parseInt(readLineFromClient);
                System.out.println( "Received from Player #" + clientcount + ": " + input);

                String reply = null;
                if(input>secret){
                    reply = "Too Much";
                    out.println("" + reply);
                    out.flush();
                }else if(input<secret){
                    reply = "Too less";
                    out.println("" + reply);
                    out.flush();
                }else{
                    reply = "You WIN WIN WIN WIN";
                    out.println("" + reply);
                    out.flush();
                    System.out.println("Player #"+ clientcount + " WIN WIN WIN WIN WIN.");
                    clientSocket.close();
                    System.exit(0);
                }
            }
    
    
        } catch (IOException e) {
            System.out.println(e);
        } finally {
            try{
                if(clientSocket != null) {
                    clientSocket.close();
                    System.out.println("xxxx Connection CLOSED" + " for Client #" + clientcount);
                }
            }catch (IOException ex) {
                System.out.println("Server IOException.");
            }
        }
    }
}