Dont understand the error

Question

Hello ,
I got a project from school , that I need to build a game like this :
http://www.levelgame.net
Ok , I divided it to two classes.
one its the level class and one its game class.
for now , I have build level 0 and the background of level 1 , but when I run it , it make some errors...
first of all , here is the code
Level class :
import javax.imageio.*;
import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.image.*;
public class Level {
     public BufferedImage backgroundImage;
     public JPanel PanelOfLevel;
     public Level(String adress)
          InputStream img = getClass().getResourceAsStream(adress);
          try
          backgroundImage=ImageIO.read(img);
          } catch (IOException e) {
               e.printStackTrace();
     public BufferedImage getImage()
          return backgroundImage;
     public void setImage (BufferedImage img)
          backgroundImage=img;
     public JPanel getLevelPane()
          return PanelOfLevel;
     public void setPanelOfLevel(JPanel newPanel)
          PanelOfLevel=newPanel;
}And here is the game class code(for now)
import javax.imageio.*;
import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.image.*;
public class Game extends JPanel {
     private Level[] levels;
     private int currentLevel;
     public Game()
          levels=new Level[20];
          currentLevel=0;
     public void paint (Graphics g)
          super.paint(g);
          Graphics2D g2d=(Graphics2D)g;
          g2d.setFont(Font.decode("arial-30"));
          levels[currentLevel]=new Level("C:/Documents and Settings/Gonen/Desktop/My things/levelgame/level0.jpg");
          g2d.drawImage(levels[currentLevel].getImage() , levels[currentLevel].getImage().getMinX() , levels[currentLevel].getImage().getMinY() , levels[currentLevel].getImage().getWidth() , levels[currentLevel].getImage().getHeight() , null);
          JButton button1=new JButton("Start Game");
          button1.setBackground(Color.RED);
          levels[currentLevel].getLevelPane().add(button1);
          button1.addMouseListener(new MouseListener() {
               public void mouseClicked(MouseEvent arg0) {
                    // TODO Auto-generated method stub
                    currentLevel++;
               public void mouseEntered(MouseEvent arg0) {
                    // TODO Auto-generated method stub
               @Override
               public void mouseExited(MouseEvent arg0) {
                    // TODO Auto-generated method stub
               @Override
               public void mousePressed(MouseEvent arg0) {
                    // TODO Auto-generated method stub
               @Override
               public void mouseReleased(MouseEvent arg0) {
                    // TODO Auto-generated method stub
          levels[currentLevel]=new Level("C:/Documents and Settings/Gonen/Desktop/My things/levelgame/level1.jpg");
          g2d.drawImage(levels[currentLevel].getImage() , levels[currentLevel].getImage().getMinX() , levels[currentLevel].getImage().getMinY() , levels[currentLevel].getImage().getWidth() , levels[currentLevel].getImage().getHeight() , null);
     public static void main(String[] args)
          JFrame frame=new JFrame("My game");
          Game mygame=new Game();
          frame.setContentPane(mygame);
          frame.setSize(400 , 400);
          frame.setVisible(true);
}and When i run it , this is the error
xception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: input == null!
     at javax.imageio.ImageIO.read(Unknown Source)
     at Level.<init>(Level.java:17)
     at Game.paint(Game.java:24)
     at javax.swing.JComponent.paintChildren(Unknown Source)
     at javax.swing.JComponent.paint(Unknown Source)
     at javax.swing.JLayeredPane.paint(Unknown Source)
     at javax.swing.JComponent.paintChildren(Unknown Source)
     at javax.swing.JComponent.paintToOffscreen(Unknown Source)
     at javax.swing.BufferStrategyPaintManager.paint(Unknown Source)
     at javax.swing.RepaintManager.paint(Unknown Source)
     at javax.swing.JComponent.paint(Unknown Source)
     at java.awt.GraphicsCallback$PaintCallback.run(Unknown Source)
     at sun.awt.SunGraphicsCallback.runOneComponent(Unknown Source)
     at sun.awt.SunGraphicsCallback.runComponents(Unknown Source)
     at java.awt.Container.paint(Unknown Source)
     at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
     at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
     at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
     at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
     at java.awt.event.InvocationEvent.dispatch(Unknown Source)
     at java.awt.EventQueue.dispatchEvent(Unknown Source)
     at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
     at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.run(Unknown Source)
I thought its becuase the adress of the picture but it cant be . here is the proof.
http://img512.imageshack.us/img512/5458/46451712ga2.jpg
see? the adress is correct.
so what is the problem here?
Please help , Gonen

Answer 1

Ok, look guys
I have tried to do something else , just to paint the first level
here is the new code of the game class
import javax.imageio.*;
import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.image.*;
public class Game extends JPanel {
     private Level[] levels;
     private int currentLevel;
     public Game()
          levels=new Level[21];
          currentLevel=0;
    public void init()
         levels[currentLevel]=new Level("C:/Documents and Settings/Gonen/Desktop/My things/levelgame/level0.jpg");
         JButton[] buttons=new JButton[21];
         buttons[currentLevel]=new JButton("Start Game");
         buttons[currentLevel].setBackground(Color.RED);
         levels[currentLevel].getLevelPane().add(buttons[currentLevel]);
     public void paint (Graphics g)
          super.paint(g);
          Graphics2D g2d=(Graphics2D)g;
          g2d.setFont(Font.decode("arial-30"));
          g2d.drawImage(levels[currentLevel].getImage() , levels[currentLevel].getImage().getMinX() , levels[currentLevel].getImage().getMinY() , levels[currentLevel].getImage().getWidth() , levels[currentLevel].getImage().getHeight() , null);
     public static void main(String[] args)
          JFrame frame=new JFrame("My game");
          Game mygame=new Game();
          frame.setContentPane(mygame);
          frame.setSize(400 , 400);
          frame.setVisible(true);
}you even look at my screenshot is my firstr message , the location of the picture is corrent
this the error now
xception in thread "AWT-EventQueue-0" java.lang.NullPointerException
     at Game.paintComponent(Game.java:33)
     at javax.swing.JComponent.paint(Unknown Source)
     at javax.swing.JComponent.paintChildren(Unknown Source)
     at javax.swing.JComponent.paint(Unknown Source)
     at javax.swing.JLayeredPane.paint(Unknown Source)
     at javax.swing.JComponent.paintChildren(Unknown Source)
     at javax.swing.JComponent.paintToOffscreen(Unknown Source)
     at javax.swing.BufferStrategyPaintManager.paint(Unknown Source)
     at javax.swing.RepaintManager.paint(Unknown Source)
     at javax.swing.JComponent.paint(Unknown Source)
     at java.awt.GraphicsCallback$PaintCallback.run(Unknown Source)
     at sun.awt.SunGraphicsCallback.runOneComponent(Unknown Source)
     at sun.awt.SunGraphicsCallback.runComponents(Unknown Source)
     at java.awt.Container.paint(Unknown Source)
     at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
     at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
     at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
     at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
     at java.awt.event.InvocationEvent.dispatch(Unknown Source)
     at java.awt.EventQueue.dispatchEvent(Unknown Source)
     at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
     at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.run(Unknown Source)
so what is the problem now?
I didnt override paint() , (tried to use here paintComponent() but same error)
The location(of the image) is correct . so what is the problem now?