Lesson 11 - Timer and SwingWorker in Java Swing

In the previous lesson, Handling Click on Coordinates in Java Swing, we completed an application that drew geometric shapes on an inherited JPanel. In today's Java turtorial, we're going to learn to use Timer and SwingWorker. We'll try both components on illustrative examples.

The Form Application Loop

Do you remember our console tutorials? If we wanted to repeat something, we simply put the code in a loop. If we wanted to create a 10-second countdown, the code would look like this:

for (int i = 10; i > 0; i--)
{
    System.out.println(i);
    try {
        Thread.sleep(1000);
    } catch (InterruptedException ex) {
        Logger.getLogger(CountdownConsole.class.getName()).log(Level.SEVERE, null, ex);
    }
}

The result:

We can't do it like this in Swing. The above operation takes 10 seconds. If we ran a similar long-running operation, the form thread would be executing it and the entire form would freez. The application would then stop responding. After a few seconds, Windows would even offer us to quit the app as it's not answering. The reason behind this is that we'd have stopped the

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