Question

I have my code.

public void keyPressed(KeyEvent e) {
    if (e.getKeyCode() == 37){
        personx -=2;
    }
    if (e.getKeyCode() == 38){
        persony -=2;
    }
    if (e.getKeyCode() == 39){
        personx +=2;
    }
    if (e.getKeyCode() == 40){
        persony +=2;
    }
    try {
        Thread.sleep((long) 0.04);
    } catch (InterruptedException e1) {
        e1.printStackTrace();
    }

The code will not move the character.
I checked if it was being called and I wrote:

public void keyPressed(KeyEvent e) {
    System.out.println("Test");
}

But it did not print Test.

Answer 1

Your code suggests that you’re working on either a Swing or an AWT GUI. Either way for KeyListeners to work you need to:

• First add the KeyListener to a component that’s on the visible GUI
• Make sure that that component is Focusable
• And that the listened to component has the GUI’s focus.

If this were a Swing GUI, I’d recommend that you not in fact use a KeyListener but rather use Key Bindings since these are more flexible than KeyListeners and allow you to re-use AbstractActions in multiple parts of your program.