How many statements in a try/catch statement?

Question

Should I put multiple statements in a try and then catch all possible exceptions, or should I put only one statement in the try statement?

Example:

try {
    MaybeThrowIOException();
    MaybeThrowFooBarException();
    return true;
} catch (IOException e) {
    // ...
} catch (FooBarException e) {
   // ... 
}

Or

try {
    MaybeThrowIOException();
} catch (IOException e) {
    // ...
}

try {
    MaybeThrowFooBarException();
} catch (FooBarException e) {
   // ... 
}

return true;

Answer 1

The more statements you put, the less specific about the cause of exception you can be potentially.

But of course it depends if the function calls/statements carry overlapped exceptions i.e. if all exceptions can be accounted for in a specific manner, then it is still ok.

In your example, you seem to be having non-overlapped exceptions so your first form is ok.

Answer 2

It depends of the case , but it's important to notice that in the first case MaybeThrowFooBarException() is nerver called if MaybeThrowIOException() throws an exception, and in the second case MaybeThrowFooBarException will be allways called unless a exception is rethrown in the first catch

Answer 3

I think the best practice is the one detailed in the book The Pragmatic Programmer, exceptions should rarely be used - but when being used it should clear to what it's suppose to be handling.

So, my vote is example #2.

Answer 4

Wrap your critical parts to keep your message clear and to the point.

Answer 5

You can handle multiple types of exceptions through single try / catch loop. But take care of order in which you are going to handle exceptions. Order of catch exception block does matter.

Answer 6

I think your first example is better practice than your second.