Craig L Russell wrote:
> Hi Bill,
>
> On May 13, 2009, at 5:39 PM, Bill Shannon wrote:
>
>> I have a bunch of code in JavaMail that looks roughly like this:
>>
>> try {
>> // do something that might fail for unknown reasons
>> } catch (Exception ex) {
>> // clean up, close connections, etc.
>> throw MyException();
>> // or...
>> return null;
>> // or...
>> continue;
>> }
>>
>> The "do something" can fail for lots of reasons - NPE, IOException,
>> etc. -
>> usually several levels deep. No matter what goes wrong I want to detect
>> the failure and clean things up, especially making sure not to leave any
>> connections open.
>>
>> FindBugs complains about this because "do something" doesn't throw
>> Exception.
>
> If do something doesn't throw Exception, you can catch RuntimeException
> or Throwable depending on whether you're prepared for just
> RuntimeException or Error conditions.
Often "do something" throws some checked exception, so I need to handle
it *and* the possible RuntimeExceptions.
If a Throwable-but-not-Exception occurs I figure everything's going
down in flames anyway and I don't worry about it. (Usually. I'm not
as consistent as I would like. :-))
> And as Tim points out, you can clean up things in a finally block
> regardless of whether an exception was thrown. Just don't "return" in
> the finally block because that will obscure an exception that was thrown.
I only need to do cleanup in the failure case.
In the cases where I would return, I return null or some other value
that indicates the failure. I purposely hide the low level exception
from the upper level code, although more often I do that by wrapping
it in my own exception.