This is a simple animation example that shows exception handling and page redirection.

/**
 * Simple Animation Example
 * 
 * @author Jing Dong
 */

import java.awt.*;
import java.net.*;
import java.applet.*;


public class SimpleAnimation extends Applet {
 
 URL errorPage;      //error html page
 int currentImage;   //current image counter
 Image animation[];  //images
 
 MediaTracker tracker;
 
 public void init(){
  currentImage = 0;
  animation = new Image[8];
  tracker = new MediaTracker(this);
  
 
  //add images to MediaTracker
  for (int i = 0; i < 8; i++ ){
  animation[i] = getImage(getCodeBase(),
           "images/free" + (i + 1) + ".gif");
  
  tracker.addImage(animation[i], 0);
  }
  
  try {
   showStatus("Now Loading...");
   
   //wait for all images downloaded
   tracker.waitForAll(); 
   
  } catch(InterruptedException E) {
   
   try {
    errorPage = new URL(getCodeBase().toString()
      + "errorPage.html");
   } catch(MalformedURLException ME) {
   
    // page redirection
    getAppletContext().showDocument(errorPage);
   } 
  }
 }
 
 
 //override paint()
 public void paint(Graphics g) {
  
  //draw the current image
  g.drawImage(animation[currentImage], 10, 10, 250, 250, this);
  
  try {
   //program stops for 0.125 second
   Thread.sleep(125);
  } catch(InterruptedException E) {
   
   //create error html page
   try {
    errorPage = new URL(getCodeBase().toString()
      + "errorPage.html");
   }catch(MalformedURLException ME) {
    
    //page redirection to error page
    getAppletContext().showDocument(errorPage);
   }
  
  }
  
  
  if (currentImage == 7) 
   currentImage = 0;
  else
   currentImage = currentImage + 1;
  
  repaint();  //patint it again!
 }
}

/**  
 *  How to use MediaTracker to load media first
 */

import java.awt.*;
import java.applet.*;

public class UseMediaTracker extends Applet {
 
 // initialize variables
 int appletWidth, appletHeight;
 // text ascent and descent
 int ascent, descent;
 // text width
 int stringWidth, x, y;
 Image bg, ship1, ship2, plane1, plane2;
 MediaTracker tracker;
 
 /**
  * (1)  overrides Applet init()  
  */
 public void init() {
  appletWidth = this.getSize().width;    //get Applet screen width
  appletHeight = this.getSize().height;  //get Applet Screen height
  
  // initialize image objects
  bg = getImage(getCodeBase(), "images/bg.gif");
  ship1 = getImage (getCodeBase(), "images/ship1.gif");
  ship2 = getImage (getCodeBase(), "images/ship2.gif");
  plane1 = getImage (getCodeBase(), "images/plane1.gif");
  plane2 = getImage (getCodeBase(), "images/plane2.gif");
  
  //initilize tracker object
  tracker = new MediaTracker(this);
  
  
  //adding images to the tracker
  tracker.addImage(bg, 0);
  tracker.addImage(ship1, 0);
  tracker.addImage(ship2, 0);
  tracker.addImage(plane1, 0);
  tracker.addImage(plane2, 0);
  
  try {
   this.showStatus("Loading...");
   tracker.waitForAll();
  }
  catch(InterruptedException E){};
 }
 
 /**
  * (2) Paint images
  */
 public void paint (Graphics g) {
  
  // if there are some errors happened when loading images
  if((tracker.statusAll(false) & MediaTracker.ERRORED) != 0) {
   FontMetrics fm = g.getFontMetrics();
   ascent =fm.getAscent();
   descent = fm.getDescent();
   stringWidth = fm.stringWidth("Loading Errors...");
   
   // calculate text center location
   x = (appletWidth - stringWidth) / 2;
   y = (appletHeight - (ascent + descent)) / 2 + ascent;
   
   this.setBackground(Color.black); //Applet background color
   g.setColor(Color.white);         //text color
   g.drawString("Loading Errors...", x, y); //centered text
   
   return;   
  }
  
  //if loading is successful, then draw images
     g.drawImage(bg, 0, 0, 320, 240, this);
     g.drawImage(ship1, 20, 140, 80, 80, this);
     g.drawImage(ship2, 180, 140, 80, 80, this);
     g.drawImage(plane1, 30, 10, 100, 100, this);
     g.drawImage(plane2, 250, 50, 50, 50, this);
     
 }

}

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