Hi,
I've been thinking about the information conveyed by exceptions, and I
think we could do much better with naming them.
Using the unchecked SlingException as a base is certainly a good idea,
but stack traces often get lost, and end users often have a hard time
reporting exactly what happened when they get an exception.
To fix this, I suggest using a class naming pattern like:
package foo.bar;
class Wiz {
static class
PackageFooBarClassWizMethodGetSomethingProblemComputeException
extends SlingException {
...
}
void getSomething() {
if(...something bad happened...) {
throw new
PackageFooBarClassWizMethodGetSomethingProblemComputeException (...);
}
}
Using a strong naming convention like this for exceptions would make
it much easier to find out where a problem happened, without having to
hunt for stack traces. Any Sling user can then report precisely where
a problem happened.
In the above example, the
PackageFooBarClassWizMethodGetSomethingProblemComputeException name
makes it very clear that there was a problem in the getSomething
method of the Wiz class in package foo.bar, and the problem is a
ComputeException. Bit of a longish name, but we all have cool IDEs,
right?
Exceptions classes like
PackageFooBarClassWizMethodGetSomethingProblemComputeException should
probably be generated, as it's somewhat boring code to type. We can
think about creating a few annotations, a java code preprocessor or
bytecode generator, a maven plugin and some javadoc extensions if we
agree on the basic idea. Maybe we should organize a hackathon soon to
design this, as it's a big change in the exceptions paradigm. And
maybe create a new JSR, as we want Sling to be based on standards.
Again, if we agree on the basics. Thinking about it...maybe JVMs could
generate those class names based on where the Exception is thrown.
Hmm....
I don't think I've seen this used in any java software yet, so it
might look unusual but being different is a great way of making Sling
more visible. I'm going to reserve the spp.org domain ASAP as we might
need a place to describe this new revolutionary technique. Tell them
you saw it here first!
WDYT?
-Bertrand
