Question

Recently I encountered a bug in an application I took over from another developer. I debugged for the reason and over an hour later I realized, that the problem wasn’t the code producing the exception, but some code executed before this returning wrong data. If I dived into this, I encountered the following:

try {
  ...
} catch (XYException e){}

If the Exception would have been propagated (a change I did), I would have found the reason for the bugs in a few minutes, as the stacktrace had pointed me to the problem. So how can I convince other developers to never catch and ignore exceptions in this way?

Answer 1

Simple rule of thumb: catch exceptions if and only if you have a meaningful way of handling them. Do whatever you need to do at your workplace to propagate this simple rule.

By utilizing tools such as PMD, you can even enforce this in the development environment of all your developers. EmptyCatchBlock (first rule under Basic Rules) is a rule that does exactly what you need. You have some more out-of-the-box rules for exceptions if you need better control on exception handling.

Nevertheless, in my experience, enforcing the use of tools such as PMD is never a substitute to proper development practices and developer education.