Java GUI JProgressBar not painting

Question

I have a GUI problem that I would like to get sorted out, but I am baffled as to what\'s happening and hope one of you can explain it. The code base is way too large to upl

Answer 1

Are you doing whatever takes that time in the EDT? Keep in mind that AWT/Swing have a dedicated thread that does GUI work – handling event handlers, repainting the GUI, etc. If you do long-running things on that thread, Swing will not repaint.

Try performing your task in another thread and update the progressbar from there accordingly. Use SwingUtilities.invokeLater or invokeAndWait to update the progressbar, though, to ensure that the GUI updates happen on the EDT. Otherwise things get very weird.