Why won;t the images render on the screen?

Question

Nothing changes from the default white screen. Any help? And one of the images is a large background, and the other is a small "person"
package game;
public class Main {
     public static void main(String[] args) {
          new Thread(new GameEngine()).start();
package game;
import java.io.*;
import javax.swing.*;
import java.awt.*;
public class GameEngine implements Runnable {
     public GameEngine() {
          GameEngine.engine = this;
     public void run() {
     private final Sprite[] loadSpriteCache() {
          try {
               Sprite[] spriteCache = new Sprite[10];
               spriteCache[0] = new Sprite(Util.getBytes("background.png"));
               spriteCache[1] = new Sprite(Util.getBytes("person.png"));
               return spriteCache;
          } catch(IOException e) {
               e.printStackTrace();
               return null;
     private final UserInterface createUserInterface() {
          return new UserInterface();
     public void paint(Graphics g) {
          for(Sprite s : spriteCache) {
               if(s != null) {
                    s.drawSprite(g, 0, 0);
                    Util.println("Rendered");
     public static GameEngine getEngine() {
          return engine;
     private static GameEngine engine;
     private Sprite[] spriteCache = loadSpriteCache();;
     private final UserInterface ui = createUserInterface();
package game;
import javax.swing.*;
import java.awt.*;
public class UserInterface extends Canvas {
     public UserInterface() {
     @Override
     public void paint(Graphics g) {
          super.paint(g);
          GameEngine.getEngine().paint(g);
     @SuppressWarnings("deprecation")
     public final JFrame createFrame() {
          JFrame frame = new JFrame();
          frame.setTitle("Simple Graphics Application");
          frame.setResizable(false);
          frame.setPreferredSize(new Dimension(700, 500));
          frame.add((Canvas)this);
          frame.pack();
          frame.show();
          return frame;
     private final JFrame frame = createFrame();
package game;
import java.io.*;
import javax.swing.*;
import java.awt.*;
public class Sprite {
     public Sprite(byte[] rawSprite) {
          this.rawSprite = rawSprite;
     public void drawSprite(Graphics g, int X, int Y) {
          g.drawImage(sprite, X, Y, null);
     private byte[] rawSprite;
     private Image sprite;
package game;
import java.io.*;
public class Util {
     public static void println(String args) {
          System.out.println(args);
     public static byte[] getBytes(String name) throws IOException {
          try {
               File file = new File(cachePath + name);
               byte[] data = new byte[(int)file.length()];
               new FileInputStream(file).read(data);
               return data;
          } catch(FileNotFoundException e) {
               println("Could not load: " + name);
               e.printStackTrace();
               return null;
     public static final String cachePath = "./data/";
}

Answer 1

This code is starting a thread with an empty run method :
package game;
public class Main {
     public static void main(String[] args) {
          new Thread(new GameEngine()).start();
}-> GameEngine.java
public void run() {
}The singleton pattern used in GameEngine needs reworking (The constructor is not private), and getEngine() returns engine without checking if it exists.
You should also not be overriding the paint methods, especially for a game as it can be called at random.
The draw method in Sprite is drawing an Image but the Sprite constructor takes a byte [] and does not actually initialize the Image variable with the byte [].
I also have absolutely no idea what the Util class is for ...
Would loading your images as ImageIcons or BufferedImages not be easier?
Edited by: Swordwrathe on Sep 2, 2009 2:58 AM