Error and Exception Handling

Abstract

Even if you wear an S on your chest when it comes to programming, you can be sure that errors will creep into all but the most trivial of applications. Some of these errors are programmer-induced—they are the result of mistakes made during the development process. Others are user-induced, caused by the end user’s unwillingness or inability to conform to application constraints. For example, the user might enter 12341234 when asked for an e-mail address, obviously ignoring what would otherwise be expected as valid input. Yet regardless of the source of the error, your application must be able to encounter and react to such unexpected errors in a graceful fashion, hopefully doing so without losing data or crashing the application. In addition, your application should be able to provide users with the feedback necessary to understand the reason for such errors and potentially adjust their behavior accordingly.