When to choose checked and unchecked exceptions

Question

In Java (or any other language with checked exceptions), when creating your own exception class, how do you decide whether it should be checked or unchecked?

My inst

Answer 1

I agree with the preference for unchecked exceptions as a rule, especially when designing an API. The caller can always choose to catch a documented, unchecked exception. You're just not needlessly forcing the caller to.

I find checked exceptions useful at the lower-level, as implementation detail. It often seems like a better flow of control mechanism than having to manage a specified error "return code". It can sometimes help see the impact of an idea for a low level code change too... declare a checked exception downstream and see who would need to adjust. This last point doesn't apply if there are a lot of generic: catch(Exception e) or throws Exception which is usually not too well-thought out anyway.