Try-catch: is this acceptable practice?

Question

We have received Java code from a software supplier. It contains a lot of try-catch blocks with nothing in the catch part. They\'re all over the pl

Answer 1

This is indeed terrible practice. Especially the catching of Exception rather than something specific gives off a horrible smell - even a NullPointerException will be swallowed. Even if it is assured that a particular thrown exception is of no real consequence, one should always log it at the very least:

try {
    // code
}
catch (MyInconsequentialException mie) {
   // tune level for this logger in logging config file if this is too spammy
   MY_LOGGER.warning("Caught an inconsequential exception.", mie);
}

However it is unlikely an exception is completely meaningless in this situation. I recommend researching exactly what exception(s) the application's code is intending to swallow here, and what they would really mean for the execution.

One important distinction is whether the try/catches are used to swallow checked exceptions. If this is the case, it probably indicates extreme apathy on the programmer's part - somebody just wanted his/her code to compile. At the least, the code should be amended:

try {
   // code
}
catch (SpecificCheckedException sce) {
   // make sure there is exception logging done farther up
   throw new RuntimeException(sce);
}

This will rethrow the exception wrapped in an unchecked RuntimeException, effectively allowing the code to compile. Even this can be considered a bandaid however - best practice for checked exceptions is to handle them on an individual basis, either in the current method or farther up by adding throws SpecificCheckedException to the method signature.

As @Tom Hawtin mentioned, new Error(sce) can be used instead of new RuntimeException(sce) in order to circumvent any additional Exception catches farther up, which makes sense for something that isn't expected to be thrown.

If the try/catch is not being used to swallow checked exceptions, it is equally dangerous and should simply be removed.

Answer 2

Horrible idea on the face of it, totally depends on what you're actually calling. Usually it's done out of laziness or habituated bad practices.