I guess this makes sense. Had there not been an NullPointerException, i
might not have noticed the error case at all :)
2010/7/22 ๏̯͡๏ Jasvir Nagra <jas...@google.com>
> On Wed, Jul 21, 2010 at 1:59 PM, Gagandeep singh <gagan.g...@gmail.com
> >wrote:
>
> > Hi
> >
> > Is there any rationale behind GadgetException extending Excepiton and
> thus
> > not being able to encapsulate runtime exceptions like
> NullPointerException
> > (checked vs unchecked exception) ?
> > Would it make sense for it to do so ? I am running into some cases where
> >
>
> The usual reason for throwing an unchecked exception instead of a checked
> one is if the exception is one which the user is not expected to be able to
> recover from. GadgetException is an expected exception which code
> regularly
> catches and recovers from. The only place that RuntimeExceptions should be
> caught in a servlet is for rendering something nice to the enduser. If you
> catch and suppress unchecked or turn them into checked ones which code
> elsewhere catches, it'll hide cause continued execution when the program is
> in an unexpected state.
>
> There might be value in wrapping some unchecked exceptions in a known way
> and catching that to distinguish unexpected errors in Shindig vs unexpected
> errors in library code however. Caja fr'instance throws
> c.g.caja.SomethingWidgyHappenedError runtime exception when it encounters a
> situation which it doesn't expected to be able to recover from.
>
> NullPointerException is throws all the way up to the stack and I was
> > wondering if i could just make GadgetException catch these.
> > For example, caja html parser sometimes throws NullPointerExceptions when
> > the dom is being parsed in GadgetHtmlParser, where i plan on adding the
> > lines in blue:
> > if (document == null) { try { document = parseDomImpl(source); } catch
> > (GadgetException e) { throw e; } catch (DOMException e) { // DOMException
> > is
> > a RuntimeException document = errorDom(e);
> > HtmlSerialization.attach(document,
> > serializerProvider.get(), source); return document; + } catch
> > (NullPointerException e) { + throw new
> > GadgetException(GadgetException.Code.INTERNAL_SERVER_ERROR, + "Caught
> > exception in parseDomImpl", e); }
> >
> > Thoughts ?
> >
> > Thanks
> > Gagan
> >
>
