Question

First off I’ve been working with Java’s Concurrency package quite a bit lately but I have found an issue that I am stuck on. I want to have and Application and the Application can have a SplashScreen with a status bar and the loading of other data. So I decided to use SwingUtilities.invokeAndWait( call the splash component here ). The SplashScreen then appears with a JProgressBar and runs a group of threads. But I can’t seem to get a good handle on things. I’ve looked over SwingWorker and tried using it for this purpose but the thread just returns. Here is a bit of pseudo code. and the points I’m trying to achieve.

• Have an Application that has a SplashScreen that pauses while loading info
• Be able to run multiple threads under the SplashScreen
• Have the progress bar of the SplashScreen Update-able yet not exit until all threads are done.

Launching splash screen

try {
    SwingUtilities.invokeAndWait( SplashScreen );
} catch (InterruptedException e) {
} catch (InvocationTargetException e) { }

Splash screen construction

SplashScreen extends JFrame implements Runnable{

    public void run() {
        //run threads
        //while updating status bar
    }
}

I have tried many things including SwingWorkers, Threads using CountDownLatch’s, and others. The CountDownLatch’s actually worked in the manner I wanted to do the processing but I was unable to update the GUI. When using the SwingWorkers either the invokeAndWait was basically nullified (which is their purpose) or it wouldn’t update the GUI still even when using a PropertyChangedListener. If someone else has a couple ideas it would be great to hear them. Thanks in advance.

I actually got ready to post better code to help out and found my solution. I thank you for all who helped.

Answer 1

No need to call the frame inside invokeAndWait but you should update progress bar state like this.

try {
   SwingUtilities.invokeAndWait( new Runnable() {
     public void run() {
//update state of the progress bar here
     }
   });
 } catch (InterruptedException e) {
 } catch (InvocationTargetException e) { }