Signaling for exception from Callable thread without blocking in main thread

Question

This is a followup for my previous question enter link description here

Now the problem is that I can't "block" (Future.get) in my main thread because it must continue with its work, but I do need the threads to signal it some how...

Answer 1

Why not just call Future.isDone() periodically from your main thread, and if done, Future.get() the result ? That will throw the original exception.