Five months ago, I began a mini-series of articles about designing objects. In this Design Techniques article, I'll continue that series by looking at design principles that concern error reporting and exceptions. I'll assume in this article that you know what exceptions are and how they work. If you would like a refresher on exceptions in general, see the companion article, "Exceptions in Java".
The benefits of exceptions
Exceptions have several benefits. First, they allow you to separate error handling code from normal code. You can surround the code that you expect to execute 99.9% of the time with a try block, and then place error handling code in catch clauses -- code that you don't expect to get executed often, if ever. This arrangement has the nice benefit of making your "normal" code less cluttered.
