Which java.lang.Error descendant are safe to catch?

Question

Its absolutely clear for me, that usually a Java program should not catch Throwable, since it is catching Error-s like OutOfMemoryError. 100% clear.

But.

If I have a multi-threaded application, it is usually a best practice, that I should have an UncaughtExceptionHandler, which does something if RuntimeException or Error happens. What I usually want to do, is simply logging. Logging RuntimeExceptions cannot really hurt, thats clear. But the question arises in me:

Which errors can I catch and log safely in an UncaughtExceptionHandler, which will not treat my whole application if I log it? Which errors are there, which does not mean, that the application must stop immediately?

For example if I get an OutOfMemoryError, I would just ask for a printStackTrace to standard out, since the memory need of logging it can kill other threads. But a StackOverflowError seems to me totally safe to be logged, since it means simply, that the stack area of the current thread became full. It is safe to log it. Which other Error descendants would you log?

Peter Lawrey · Answer 1 · 2013-10-03T20:05:17.390

1

Any Throwable is safe to catch if you can do something constructive with it. Any Throwable where you can't do something useful, should not be caught.

BTW: For catch all logging, I catch(Throwable) for logging purpose when I know the remaining code would otherwise discard the Throwable/Error/Exception.

edited Oct 03 '13 at 20:05

answered Oct 03 '13 at 19:56

Peter Lawrey

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I dont understand the "when I know it would otherwise discard it." part. What do you mean by "it"? – Gábor Lipták Oct 03 '13 at 19:59
@GáborLipták By "it" I mean the Throwable like an Error or Exception. – Peter Lawrey Oct 03 '13 at 20:00
hehe. I have just realized, that this part contains "it" twice. So I meant the first "it". What does it mean? – Gábor Lipták Oct 03 '13 at 20:03
@GáborLipták I have replaced the "it" ;) – Peter Lawrey Oct 03 '13 at 20:05

Which java.lang.Error descendant are safe to catch?

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