Help needed for Background Tasks in Java!

[warehouse peon]

Hi friends,
I have recently completed the C++ programming language and turned towards the Java, so not having much knowledge of Java. I have created a GUI With JFC. I have also used the SwingWorker for doing some application. All I want to know is about the Background Tasks in Java! Hope that somebody would response me sooner.!!

[MELTRONICS]

Many times you use the TumbleItem applet for loading the set of graphic files used in an animation. There are chances of getting delayed before the GUI appears, if the graphic files are loaded from an initial thread. And the GUI may be unresponsive temporarily, the graphic files are loaded from the event dispatch thread. The object's doInBackground method, executing in a worker thread, loads the images into an ImageIcon array, and returns a reference to it.

[Viensterrr]

You can retrieve the object returned by doInBackground in two ways which are described as follows :

1. SwingWorker.get - You will have to invoke this method without any arguments. If the background task is not finished, get blocks until it is.
2. SwingWorker.get - You will have to invoke this method with arguments indicating a timeout. This blocks until the background task is not finished, unless the timeout expires first, in which case get throws java.util.concurrent.TimeoutException.

[void]

I have provided you the coding that defines and executes the SwingWorker object. The following coding does the same :

SwingWorker sworker = new SwingWorker<ImageIcon[], Void>() {
    @Override
    public ImageIcon[] doInBackground() {
        final ImageIcon[] innerImgs = new ImageIcon[imgico];
        for (int i = 0; i < imgico; i++) {
            innerImgs[i] = loadImage(i+1);
        }
        return innerImgs;
    }

    @Override
    public void done() {
        animator.removeAll();
        loopslot = -1;
        try {
            imgs = get();
        } catch (InterruptedException ignore) {}
        catch (java.util.concurrent.ExecutionException e) {
            String why = null;
            Throwable cause = e.getCause();
            if (cause != null) {
                why = cause.getMessage();
            } else {
                why = e.getMessage();
            }
            System.err.println("Error while retrieving file: " + why);
        }
    }
};

[Allan.d]

I have gone through the post which was posted by 'Viensterrr'. He has described the two ways for retrieving the object returned by doInBackground which is correct. But you should keep in mind when invoking either overload of get from the event dispatch thread; until get returns, no GUI events are being processed, and the GUI is "frozen".Don't invoke get without arguments unless you are confident that the background task is complete or close to completion.