I can't get my Button to work?

Question

Hello everyone,
I been trying to get my Button working, but I don't understand what's wrong. I've tried a bunch of stuff, each with failure. Can any of you guys help me out here? I know that it's a little bit of a mess, but for some reason, it gives me a NullPointerException when I execute it. If I comment out 4 lines of code, about the getContentPane, it works without making a button. Problem is, I want to keep the Button in there. What should I do?
Thanks
import com.brackeen.javagamebook.graphics.ScreenManager;
import com.brackeen.javagamebook.graphics.ScreenManager;
import com.brackeen.javagamebook.sound.SoundManager;
import com.brackeen.javagamebook.graphics.NullRepaintManager;
import com.brackeen.javagamebook.input.*;
import com.brackeen.javagamebook.input.GameAction;
import com.brackeen.javagamebook.graphics.*;
import com.brackeen.javagamebook.sound.*;
import com.brackeen.javagamebook.test.GameCore;
import java.util.List;
import java.util.ArrayList;
import javax.swing.border.Border;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.io.File;
import java.awt.event.KeyListener;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.sound.sampled.AudioFormat;
import javax.sound.midi.Sequence;
import java.applet.AudioClip;
import javax.sound.midi.Sequencer;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.lang.reflect.InvocationTargetException;
public class Graphic2 implements ActionListener
     public static void main(String[] args)
new Graphic2().run();
private JPanel startButtonSpace;
private static final long DEMO_TIME = 30000;
private static final String EXIT = "Exit";
private ScreenManager screen;
private ActionListener action;
private Image Background, Title, Start;
private boolean isRunning;
private Sequence music;
private SoundManager soundManager = new SoundManager(PLAYBACK_FORMAT);
private MidiPlayer midiPlayer;
private Sound titleMusic;
//Uncompressed, 44100Hz, 16-bit, Sterio, Signed, Little-Endian
private static final AudioFormat PLAYBACK_FORMAT =
new AudioFormat(44100, 16, 2, true, false);
protected InputManager inputManager;
protected GameAction configAction;
protected GameAction exit;
private JButton startButton;
private static final DisplayMode POSSIBLE_MODES[] = {
new DisplayMode(1024, 768, 32, 0),
new DisplayMode(1024, 768, 24, 0),
new DisplayMode(1024, 768, 16, 0),
new DisplayMode(800, 600, 32, 0),
new DisplayMode(800, 600, 24, 0),
new DisplayMode(800, 600, 16, 0)
public void loadImages()
// load images
Background = loadImage("Title Screen.jpg");
Title = loadImage("Title.gif");
Start = loadImage("Start.gif");
public Image loadImage(String fileName)
return new ImageIcon(fileName).getImage();
public void animationLoop()
long startTime = System.currentTimeMillis();
long currTime = startTime;
while (isRunning)
long elapsedTime = System.currentTimeMillis() - currTime;
currTime += elapsedTime;
// draw and update screen
Graphics2D g = screen.getGraphics();
draw(g);
g.dispose();
screen.update();
// take a nap
try
Thread.sleep(20);
catch (InterruptedException ex) { }
public void initSounds()
//midiPlayer = new MidiPlayer();
titleMusic = soundManager.getSound("movie02.wav");
//music = midiPlayer.getSequence("potc.mid");
public void run()
     NullRepaintManager.install();
     isRunning = true;
     initSounds();
     NullRepaintManager.install();
     screen = new ScreenManager();
     JFrame frame = screen.getFullScreenWindow();
// create buttons
startButton = createButton("Start.gif");
startButton.setLocation(460, 500);
//frame.getContentPane().setLayout(new FlowLayout());
//frame.getContentPane().add(startButton);
try
DisplayMode displayMode =
screen.findFirstCompatibleMode(POSSIBLE_MODES);
screen.setFullScreen(displayMode);
loadImages();
soundManager.play(titleMusic);
//if (frame.getContentPane() instanceof JComponent)
     //((JComponent)frame.getContentPane()).setOpaque(false);
animationLoop();
finally
screen.restoreScreen();
soundManager.stop();
frame.validate();
Window window = screen.getFullScreenWindow();
     public void draw(Graphics2D g)
// draw background
g.drawImage(Background, 0, 0, null);
// draw image
g.drawImage(Title, 342, 244, null);
//g.drawImage(Start, 460, 500, null);
public void actionPerformed(ActionEvent e)
Object src = e.getSource();
if (src == startButton)
exit.tap();
public void checkSystemInput()
if (exit.isPressed())
stop();
public void stop()
isRunning = false;
public void createGameActions()
exit = new GameAction("exit",
GameAction.DETECT_INITAL_PRESS_ONLY);
inputManager.mapToKey(exit, KeyEvent.VK_ESCAPE);
public JButton createButton(String name)
// load the image
String imagePath = name;
ImageIcon iconRollover = new ImageIcon(imagePath);
int w = iconRollover.getIconWidth();
int h = iconRollover.getIconHeight();
// get the cursor for this button
Cursor cursor =
Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
// make translucent default image
/*Image image = screen.createCompatibleImage(w, h);*/
Graphics2D g = screen.getGraphics();
/*g.drawImage(iconRollover.getImage(), 0, 0, null);*/
// create the button
JButton button = new JButton();
button.addActionListener(this);
button.setIgnoreRepaint(true);
button.setFocusable(false);
button.setBorder(null);
button.setContentAreaFilled(false);
button.setCursor(cursor);
button.setIcon(iconRollover);
button.setRolloverIcon(iconRollover);
button.setPressedIcon(iconRollover);
return button;
}

Answer 1

1) Swing related questions should be posted in the Swing forum
2) Use the "code" formatting tags when posting code so the code is readable.
3) Post [url http://www.physci.org/codes/sscce.jsp]Simple, Executable Sample that shows your problem. The code you posted uses non-standard API's so we can't execute your code to see the incorrect behaviour.
4) Read the Swing tutorial on [url http://java.sun.com/docs/books/tutorial/uiswing/components/button.html]How to Use Buttons. Or maybe the section on "How to Use Layout Managers" will solve your problem. Either way read the tutorial.