I'm creating a window (JOptionPane), in response to a collision. However, if the player is holding a key down when the window pops up, the input doesn't trigger a key release when the key is released.

I don't think you can just check it with a isRelease function in the input, since the input is kind of corrupt. Can you help me?

The way I check if the key is down:

if(input.isKeyDown(Input.KEY_A)&& TestLevel.isFighting == false){
            if(owner.canMoveLeft){
                position.x -= speed * delta;
            }
        }

I am not handling the key release by myself, but if I check if the key is down it should work. But it doesn't.