I have a situation where I'm opening a JOptionPane with a warning message and then some processing occur after the ok button is clicked. What's happening is the JOptionPane appears frozen with OK button pressed until after the processing completes. How can I make sure the JOptionPane disappears afte the ok button is pressed?
You're probably doing this processing right in an event handler, which ties up the event-handing thread and blocks any screen updates until the processing is over. Any time you do any nontrivial computation in a GUI app, you should create a new Thread and do the computation in that Thread, freeing up the event thread to do things like make JOptionPanes disappear.