Why does Null restrict my movement?

Question

With the help of these forums I was able to place JLabels with the use of frame.getContentPane().setLayout(null); The problem I'm having now is that the JLabel (whose image path is penguin.gif) can move around in all directions except down. Can anyone help me fix this?
Here is the code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class PenguinWars extends JFrame implements KeyListener {
     public boolean left = false, right = false, up = false, down =false;
     private static boolean start = false, end = false;
     public static int w = 300, h = 500, x = 200, y = 520, xw = 20, xh = 25; //w,h for frame; x,y for penguin position, xw, xh for penguin size
     private static int startLabX=200;
     private static int startLabY=520;
     private JLabel example=new JLabel();
     private static JLabel lab;
  public PenguinWars() {
    // Create a MovingMessagePanel for displaying a moving message
    add(new MovingMessagePanel("O", "X"));
    example.setSize(20,25);
    example.setLocation(0,0);
    example.setBackground(Color.black);
    add(example);
  public void keyControl() {
         if (0 < x) {
             if (left) {
                 x -= 3;
         if (w > x + xw) {
             if (right) {
                 x += 3;
         if (25 < y) {
             if (up) {
                 y -= 3;
         if (h > y + xh) {
             if (down) {
                 y += 3;
   public void keyPressed(KeyEvent ke) {
      switch (ke.getKeyCode()) {
             case KeyEvent.VK_LEFT:
                 if (-186 < startLabX) {
                 left = true;
                startLabX-=5;
                 else
                     left = false;
          lab.setLocation(startLabX,startLabY);
                 break;
             case KeyEvent.VK_RIGHT:
                 if (186 > startLabX) {
                 right = true;
                 startLabX+=5;
                 else
                     right = false;
          lab.setLocation(startLabX,startLabY);
                 break;
             case KeyEvent.VK_UP:
                 if ( -550< startLabY){
                 up = true;
                 startLabY-=5;
                 else
                     up =false;
          lab.setLocation(startLabX,startLabY);
                 break;
             case KeyEvent.VK_DOWN:
                 if (0 > startLabY) {
                 down = true;
                 startLabY+=5;
                 else
                     down = false;
          lab.setLocation(startLabX,startLabY);
                 break;
          /*     case KeyEvent.VK_ENTER:
                start = true;
                end = false;
                break;
     public void keyReleased(KeyEvent ke) {
         switch (ke.getKeyCode()) {
             case KeyEvent.VK_LEFT:
                 left = false;
                 break;
             case KeyEvent.VK_RIGHT:
                 right = false;
                 break;
             case KeyEvent.VK_UP:
                 up = false;
                 break;
             case KeyEvent.VK_DOWN:
                 down = false;
                 break;
     public void keyTyped(KeyEvent ke) {
  /** Main method */
  public static void main(String[] args) {
    PenguinWars frame = new PenguinWars();
    int optionType = JOptionPane.YES_NO_OPTION; // YES+NO+CANCEL
    int messageType = JOptionPane.QUESTION_MESSAGE; // no standard icon
    int res = JOptionPane.showConfirmDialog(null, "Welcome to Penguin Wars!\n"+
            "How To Play The Game: \n"+
            "You can begin the game by pressing the SPACE BAR. \n"+
            "The goal of this game if to save our penguin from the garbages that are contaminating its environment.  \n"+
            "Move the penguin using the arrow keys to avoid all the garbages. \n"+
            "The game will be over when the penguin eats too much garbages. \n"+
            "You can earn points by feeding healthy fish to the penguin. \n", "Directions",
                                        optionType, messageType);
    if (res == JOptionPane.NO_OPTION) {
        System.exit(0);
    if (res == JOptionPane.CLOSED_OPTION) {
        System.exit(0);
    *lab=new JLabel();*
    *lab.setSize(25,25);*
    *lab.setLocation(startLabX, startLabY);*
    *lab.setIcon(new ImageIcon("penguin.gif"));*
    frame.setTitle("Penguin Wars");
    frame.getContentPane().setLayout(null);
    frame.getContentPane().add(lab);
    frame.setLocationRelativeTo(null); // Center the frame
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(400, 600);
    frame.setLocation(200, 100);
    frame.addKeyListener(new PenguinWars());
    frame.setVisible(true);
    ImageIcon icon = new ImageIcon("garbage.gif");
     // allocate array for enemy labels
     JLabel[] enemies = new JLabel[5];
     // all elements of this array are null, not instantiated
     // initialize the array by instantiating the elements
     for(int i = 0; i < enemies.length; i++)
      int en_posx = (int)(Math.random()*300)+1;;
      int en_posy = 0;
    enemies=new JLabel();
enemies[i].setSize(25,25);
enemies[i].setLocation(en_posx,en_posy);
enemies[i].setIcon(new ImageIcon("garbage.gif"));
frame.getContentPane().add(enemies[i]);
     } //end for
//setting background image
Color background = new Color(150,100,255);
Container con = frame.getContentPane();
con.setBackground( background );

Answer 1

Your code is too large and won't compile. Your best bet is to try to solve your problem with a very simple class -- one that does nothing but moves a simple JLabel around a JPanel, one that has no extraneous dependencies, such as "MovingMessagePanel" or other classes. This way if the code still fails, you can post it here, we can more easily understand it and actually try it out, and we can more easily help provide you with a solution. This is called creating an SSCCE (please see the link).
edit: you may have a solution above by tjacobs, but I still stand by my recommendations, if not for this thread then for future threads.
edit 2: You should seriously consider using key bindings and not a key listener.
edit 3: You never replied to my post in your most recent thread: [http://forums.sun.com/thread.jspa?threadID=5419871&messageID=10885069#10885069]
By responding and acknowledging, you'll encourage folks to help you in the future. Just fyi.
Edited by: Encephalopathic on Dec 13, 2009 10:59 AM
Edited by: Encephalopathic on Dec 13, 2009 11:00 AM