When should Throwable be used instead of new Exception?

Given: Throwable is Exception's superclass.

When I read texts on writing your own 'exceptions', I see examples of Throwable being used in the catch block and other texts show new Exception() being used in the catch block. I have yet to see an explanation of when one should use each.

My question is this, when should Throwable be used and when should new Exception() be used?

Inside the catch or else block using either:

throw throwable;

throw new Exception();

java exception throwable

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You shouldn't use Exceptions as a "return type" either...

If the condition you're throwing for is common, you are spending a huge amount of resources to return that condition to the calling routine. Exceptions are expensive to construct.

I've seen cases where tight loops that threw exceptions as a "negative" for e.g. ID allocation, this routine occupied about 99% of the CPU time .. when changed to a documented return constant instead, this dropped to 25%.

answered 2010-03-04T16:05:33.667

When should Throwable be used instead of new Exception?

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