Java's Swing Threading

Question

My understanding is that if I start up another thread to perform some actions, I would need to SwingUtilities.invokeAndWait or SwingUtilities.invokeLater<

Answer 1

In my opinion you should almost never use invokeAndWait(). If something is going to take awhile that will lock your UI.

Use a SwingWorker for this kind of thing. Take a look at Improve Application Performance With SwingWorker in Java SE 6.

Answer 2

I keep the simple Thread inside EventQueue.invokeLater(...) and that worked smoothly...

java.awt.EventQueue.invokeLater(new Runnable() {
    public void run(){

        new Thread(new Runnable(){
            public void run(){

                try{
                    EdgeProgress progress = EdgeProgress.getEdgeProgress();
                    System.out.println("now in traceProgressMonitor...");
                    while(true){
                        // here the swing update
                        if(monitor.getState() == ProgressMonitor.STATE_BUSY){
                            System.out.println(monitor.getPercentDone()/2);
                            progress.setProgress(monitor.getPercentDone()/2);
                        }else{
                            break;
                        }
                        Thread.sleep(5);
                    }
                }catch(InterruptedException ie){}

            }
        }).start();

    }
});

Answer 3

You should consider using SwingWorker since it will not block the UI thread, whereas both SwingUtilities methods will execute on the EDT thread, thus blocking the UI.