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Message:

Where to catch exceptions

Posted by Andre' Simmons on May 20, 1999 at 1:36 PM

> Bill Venners wrote:

> > My own thought is that one should catch exceptions in the
> > method that knows how to handle that exception, and that is
> > usually going to be at the application level. Exceptions let
> > you transfer control from the part of a program where an
> > error or problem is detected to another part of the program
> > that knows how to handle the error.

> This is good as far as it goes but I wonder about how locally
> you should catch exceptions. Suppose you have a method that
> makes several calls to an API, and each call can throw a couple
> of different exceptions. Do you put a little try-catch block
> around each call, or a big one around the whole method? Any
> style guidelines? Thanks.

In this case I believe it truly depends on the situation. If you are using an API that is independent of each call (i.e. one call has no bearing on the next call) then I would put all the calls under one try/catch. I am assuming that the problem is somehow related the the library itself not by recalling. If one call affects the previous call then I would stair-step the calls making sure to isolate the calls to better debug. Cascade exceptions could easily occur in this situation.