Swing "blocking", I think I need to thread, but not sure how much

Answer 1

One suggestion for you, to figure out how to do this, and in case you are using NetBeans or have access to NetBeans, is to look at the default Java Desktop Application template. It creates a pre-wired desktop app with progress bar built into a status bar, that will automatically get updated when any "Action" code gets executed. It leverages the Action API which is also pre-wired to run in a background thread.

By looking at that auto-generated code you'll be able to properly and easily implement it in your own.

Answer 2

Yes, you should put your time intense reading into a separate thread. Now you do everything in the event-dispatching thread (EDT), which would update your GUI but is busy reading your data.

You can use SwingWorker for this. Have a look at Using a Swing Worker Thread which looks like what you need.

Answer 3

I would say: yes, your thoughts on offloading the reading of large files to a separate thread are correct. You should never perform long tasks on the Event Dispatch Thread, since while that thread is busy, the GUI will be unresponsive, and you application will feel slow.

This sounds like good case for SwingWorker. This class allows you to perform slow requests (such as disk or network access) on a separate thread, with progress updates being fed back to the GUI with the EDT. SwingWorker looks after all complexities of switching between threads. All you have to do is implement your business logic in the appropriate places.

Sun has a tutorial on SwingWorker.