unable to take keyboard inputs in java using KeyListener

Question

i am trying to take keyboard inputs to change the boolean's value but keylisteners are not working
those bolleans values will be used later in other class
heres the method i am having issues with

public boolean upPressed, downPressed, leftPressed, rightPressed;

    @Override
    public void keyPressed(KeyEvent e) {
        int code = e.getKeyCode();
        if(code == KeyEvent.VK_W){
            upPressed = true;}
        
        else if(code == KeyEvent.VK_S){
            downPressed = true;}
        
        else if(code == KeyEvent.VK_A){
            leftPressed = true;}
        
        else if(code == KeyEvent.VK_D){
            rightPressed = true;}
        
    }

i am using a different class which extends JPanel, frame is in a different class and key listener is in a different class and i have this.setFocusable(true);this.addKeyListener(keyH);

and if u want, here's the full code : https://github.com/PROMAN8625/2dGAME

Answer 1

Your code snippet looks fine. Maybe you didn't add KeyListener to the frame.

Here is a working example:

import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class KeyListenerExample implements KeyListener
{
    public boolean upPressed, downPressed, leftPressed, rightPressed;

    @Override
    public void keyTyped(KeyEvent e) {
    }

    @Override
    public void keyPressed(KeyEvent e)
    {
        int code = e.getKeyCode();
        if (code == KeyEvent.VK_W) {
            upPressed = true;
        }
        else if(code == KeyEvent.VK_S){
            downPressed = true;}

        else if(code == KeyEvent.VK_A){
            leftPressed = true;}

        else if(code == KeyEvent.VK_D){
            rightPressed = true;}

        System.out.println("The key Pressed was: " + e.getKeyChar());
        System.out.println("upPressed: " + upPressed);
        System.out.println("downPressed: " + downPressed);
        System.out.println("leftPressed: " + leftPressed);
        System.out.println("rightPressed: " + rightPressed);
        System.out.println("\n");

    }

    @Override
    public void keyReleased(KeyEvent e) {
    }

    public static void main(String[] args)
    {
        //Setting the Frame and Labels
        Frame f = new Frame("Demo");
        f.setLayout(new FlowLayout());
        f.setSize(500, 500);
        Label l = new Label();
        l.setText("This is a demonstration");
        f.add(l);
        f.setVisible(true);

        //Creating and adding the key listener
        KeyListenerExample k = new KeyListenerExample();
        f.addKeyListener(k);
    }
}