服务器-客户端 Java

Question

I made a basic server and client program in Java and when you start the server than the client it connects the two if the user types in the password "root" and i saved that value as password, and I'm trying to make it so when the connection starts on the server side it outputs "The password is" than the value of password, but everytime i run it the program outputs "The password is null", why is it giving me this?? I changed the string to static and it still gave me null, please help and explain??

Server side code

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;


public void lookForConnection(){
    Socket connection;
    clientMethod cM = new clientMethod();
    {
        try
        {
            System.out.print("Program running...");
            ServerSocket serverSocket = new ServerSocket(6789);
            while(true) 
            {
                connection = serverSocket.accept();
                System.out.println("Connected Succesfully!");
                System.out.println(connection.getInetAddress().getHostName());
                System.out.println("The password for this connection is " + cM.password);              
            }
        }
        catch(IOException ex)
        {
            System.out.println (ex.toString());

        }

    }
}

Client side code

import java.io.EOFException;
import java.util.Scanner;
import java.io.IOException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;

public class clientMethod {
    public String serverIP;
    public String password;
    public Socket connection; 
    public void Client(String host)
    {
        serverIP = host;
    }
    public void startRunning() {
        try{
            Scanner console = new Scanner(System.in);
            System.out.print("Please provide the admin password: ");
            password = console.next();
            if(password.compareTo("root") == 0 ) {
                connectToServer();          
            //}
            }
        }
        catch(EOFException eofException){
            System.out.print("\n Client terminated the connection");
        }
        catch(IOException ioException) {
            ioException.printStackTrace();
        }
    }
    private void connectToServer() throws IOException {
        System.out.println("Attempting connection...");
        connection = new Socket(InetAddress.getByName(serverIP), 6789);
        System.out.println("Connected to " + connection.getInetAddress().getHostName());

    }
}

Answer 1

Probably because you never send your password to your Server, you only print the value of the variable password of your local variable cM that is never set so it is null for sure.

Check this tutorial to see how to send data to a server but basically the idea is to write your data from your client using the OutputStream that you get from Socket#getOutputStream() , it will send data to the server and from the server you read it from Socket#getInputStream() .