Should non-Swing code be executed on non-EDT threads?

Question

I know the Swing single-thread rule (from Java Concurrency in Practice):

Swing components and models should be created, modified, and queried only from the event-dispatching thread.

Is the converse also true? I maintain some transaction logging code that writes event information to a file and it sometimes does this on the EDT. Is this a bad practice?

Answer 1

That depends on what you are doing. Basically while you are using the EDT thread then it cannot do anything else. That means button clicks, processing, user interface updates, etc will all be stalled.

So for long-running tasks you should use a different thread (for example SwingWorker) but for anything that is unlikely to stall or take a long time doing it on the EDT is fine.