Objectopia

My previous post about exceptions in Java begs the question: Where do so called “business exceptions” fit in with all of this?

Business Exceptions are Checked Exceptions

Following on from my reasoning, the user is something that you have no control over. Therefore you expect these types of exceptions to occur. Making them checked exceptions forces you to handle them in some way.

A classic example of these errors are validation errors. These should be checked exceptions because usually you’d need to force the user to fix the entered data before the form can be submitted.

Dealing with Checked Exceptions

The problem of checked exceptions is: how do you handle them ? You’ve got to catch them somewhere (or rethrow), how do you know what to do with them ? This is usually a requirements question; this should be a hint to you to go back to the business and get some clarification on the requirements.