Disagreement with Joel

In his most recent article, Joel Spolsky declares that exceptions are bad. He’s gotten a lot of pushback on this (Charles Miller has a nice collection of this), which is not surprising. Many of us have worked with error return codes and exceptions both and have a strong preference for exceptions.

I think it is a powerful testament to how much people appreciate Joel’s writing that so many people have spoken out on this one saying “I always enjoy Joel’s writing, but…” Joel has had a great collection of articles that show he really has a clue.

Contrary positions, like this one, from respected folks like Joel often encourage a rethinking of your position on something. In this case, I doubt there will really be much rethinking… I, for one, have been down the error code path before and don’t want to go back.

When creating methods, my current thinking on exceptions is to use checked exceptions for things that I think the application can gracefully recover from. Contrary to what Joel is talking about, in Java the programmer does know which exceptions can be thrown by a given method.

If the exception is the kind of thing that it really doesn’t make sense to continue after, throwing an unchecked exception eliminates a lot of messiness in the code. Just make sure that the UI catches the exception and provides a nice, descriptive message to the user so that support people can help if need be.