Java keyListener在BasicConstruct上不起作用

Question

I am testing some things with j3d and i cant seem to get a keylistener to work for a BasicConstruct. It isn't doing anything when i press ay of the 38 key (up), not even the debug output to console. heres part of my main class "BasicConstruct". here is where it should be registering:

@SuppressWarnings("deprecation")  //for the bc.show(true);
public static void main(String[] argv) {
    bc = new BasicConstruct();

    bc.setTitle("3D Rendering");

    bc.setSize(500, 500);
    bc.setLocationRelativeTo(null);
    bc.setDefaultCloseOperation(EXIT_ON_CLOSE);
    bc.refresh(addBox(0f, 0f, 0f, 0.005f, 0.5f, 0.5f, 
        new Color3f(1, 0, 0), new Color3f(1, 0, 0)));  //draws a box on screen. not relevant to the queston

    bc.setFocusable(true);
    bc.addKeyListener(new PopClickListener());

    bc.addDirectionalLight(new Vector3f(0f, 0f, -1f), new Color3f(1f, 1f, 0f));
    bc.finalise(rootBranchGroup);
    bc.show(true);
}

and the PopClickListener class (havent bothered to rename it):

import java.applet.Applet;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.Random;
import javax.vecmath.Color3f;
public class PopClickListener extends Applet implements KeyListener {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == 38){
            BasicConstruct.placeblockonscreen(BasicConstruct.bc, randInt(.1f, 0f),
                randInt(1f, 0f), randInt(.1f, 0f), randInt(.1f, 0f), randInt(.1f, 0f),
                randInt(.1f, 0f), new Color3f(10, 10, 10), new Color3f(10, 10, 10));
                System.out.println("hey"); //debug
        }
    }
    public void keyReleased(KeyEvent e) {}
    public void keyTyped(KeyEvent e) {}

    public static float randInt(float min, float max) {

        Random rand = new Random();

        float finalfloat = rand.nextFloat() * (max - min) + min;

        return finalfloat;
    }
}

Answer 1

Well first of all, make sure that the keyPressed() is getting called by placing a System.out.println("KEY PRESSED"); outside the if statement, but still inside the method. If that works, change the code so that it displays the key character, the key code, and some other things about the KeyEvent. This will tell you which key is being pressed. Finally, I suggest using KeyEvent.VK_UP instead of the integer 38 to insure expected results.