JApplet / application init / start progress status feedback

Question

We used to put up a separate JFrame during the initization/startup of our applets/applications for status messages. While o.k. for Java Webstart / application modes (& maybe standalone applet mode), this was not pretty for customers embedding our apps in portals.
So, the goal became to show custom progress/status on the "gray screen" initial applet contentpane until our app desktop is ready to show. Known threading / painting issues during applet startup made this task somewhat non-trival.
Searched around here on the jdc & found a nice little Moving Ball class & used that as a base for the play app below. Thought I'd post this back to jdc in case anyone else finds it useful. The JApplet code has a main, so same code should work for the app whether deployed as a (plug-in) applet, application JAR or Web Start app.
The code should show a RED moving ball during init, a YELLOW one during start and a GREEN one after start method is done (w/ball x position update in scrolling pane)....
import javax.swing.*;
import java.awt.*;
import java.awt.event.WindowListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
    cforster: Uses Ball painting code (from jdc) & separate status area to simulate JApplet
    startup msgs to be shown to user during applet init...
    Point is to show status during applet/application initialization (init / start) methods...
    Can JAR this up & try in appletviewer or using 1.4.2+ plugin, etc.
    With main() also usable in application / Webstart mode....
    If going the application route (or double-click JAR route), need JAR manifest.mf like:
    Manifest-Version: 1.0
    Main-Class: Today
    Created-By: 1.4.2 (Sun Microsystems Inc.)
public class Today extends JApplet {
    private static Today inst;
    //  Ball color will change from RED (init) -> YELLOW (start) -> RED (start done)
    Color ballColor = Color.RED;
    final int colorSleep = 3000;    // Time to waste in init & start methods
    final int pauseSleep = 25;      // Time between Ball moves/draws
    JTextArea jta = new JTextArea("===  Status  ===" + "\n", 50, 132);
    MovingBall movingBall = new MovingBall(jta);
    public static Today getInstance() {
        if (inst == null) inst = new Today();
        return inst;
    public Today() {
        super();
    public void init() {
        setVisible(true);
        getContentPane().setLayout(new BoxLayout(getContentPane(), BoxLayout.Y_AXIS));
        movingBall.setPreferredSize(new Dimension(400, 100));
        movingBall.setBackground(Color.lightGray);
        getContentPane().add(movingBall);
        jta.setEditable(false);
        jta.setBackground(Color.lightGray);
        getContentPane().add(new JScrollPane(jta));
        movingBall.start();
        validate();
        try {
            Thread.sleep(colorSleep);
        catch (InterruptedException ie) {      }
    public void start() {
        ballColor = Color.YELLOW;
        validate();
        try {
            Thread.sleep(colorSleep);
        catch (InterruptedException ie) {       }
        ballColor = Color.GREEN;
    public void stop() {
        movingBall.stop();
    public static void main(String args[]) {
        final Today CallingApplet = Today.getInstance();
        JFrame frame = new JFrame("Moving Ball / Load status");
        frame.getContentPane().setLayout(new BorderLayout());
        frame.getContentPane().add("Center", CallingApplet);
        // Use an adapter to close the window
        WindowListener listener = new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
        frame.addWindowListener(listener);
        frame.setBackground(Color.lightGray);
        frame.pack();
        frame.setSize(400, 400);
        frame.show();
        CallingApplet.init();
        CallingApplet.start();
    class MovingBall extends JPanel implements Runnable {
        final int xPos_Start = 8;
        int xPos = xPos_Start, yPos = 100, rad = 10;
        boolean moveForward = true;
        Thread thread;
        Graphics dbg;
        Image dblImage;
        JTextArea jta = null;
        MovingBall ball = this;
        // Takes in JTestArea that is supposed to be the status msg area...
        // In practice, the staus area & updates are elsewhere...
        public MovingBall(JTextArea jta) {
            this.jta = jta;
        public void start() {
            Thread ballThread = new Thread(this);
            ballThread.start();
        public void run() {
            Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
            yPos = getHeight() / 2 + (rad / 2) + rad;
            while (true) {
                if (moveForward)
                    xPos++;
                else
                    xPos--;
                if (xPos > getWidth() - (2 * rad))
                    moveForward = false;
                else if (xPos < xPos_Start + (2 * rad)) moveForward = true;
                SwingUtilities.invokeLater(new Runnable() {
                    public void run() {
                        if (xPos % 20 == 0) {
                            jta.append("xPos = " + xPos + "\n");
                            jta.setCaretPosition(jta.getText().length());
                        ball.paintImmediately(ball.getBounds());
                try {
                    Thread.sleep(pauseSleep);
                catch (InterruptedException ie) {
                    break;
        public synchronized void stop() {
            thread = null;
/*  Not needed for Swing Component (only AWT ?)
          public void update(Graphics g)
               if(dblImage == null)
                    dblImage = createImage(this.getSize().width, this.getSize().height);
                    dbg = dblImage.getGraphics();
               dbg.setColor(getBackground());
               dbg.fillRect(0, 0, this.getSize().width, this.getSize().height);
               dbg.setColor(getForeground());
               paintComponent(dbg);
               g.drawImage(dblImage, 0, 0, this);
        public void paintComponent(Graphics g) {
            g.setColor(getBackground());
            g.fillRect(0, 0, getWidth(), getHeight());
            g.setColor(ballColor);
            g.fillOval(xPos - rad, yPos - rad, 2 * rad, 2 * rad);
}If anyone plays with this & finds issues/problems or makes improvements to its mechanism, would be nice to post back to this thread.

Answer 1

hello,
I found that while configuration of AM there was an warning
Command deploy executed successfully with following warning messages: Error occurred during application loading phase. The application will not run properly. Please fix your application and redeploy.
WARNING: com.sun.enterprise.deployment.backend.IASDeploymentException: ContainerBase.addChild: start: LifecycleException:  java.lang.NoClassDefFoundError
Successfully deployed /amserverthis might help in resolving the issue.
regards,
sumant