On Feb 10, 2007, at 1:23 AM, Tim McConnell wrote:
Hi, I've attached a patch and two new classes to the GERONIMO-2816
JIRA that provides support for the @EJB and @EJBs
annotations if anyone would like to review. The intent is to
demonstrate a final/permanent technique that can be extended and
used throughout Geronimo to support annotations for JSR-88. This
patch and new code works for Tomcat and circumvents the annotation
processing that is currently in EjbRefBuilder (which did not update
the deployment descriptor with the discovered annotations, but only
updated the JNDI references). I'd appreciate some feedback before I
start propagating this technique to the other module builders to
support the remainder of the annotations. I already have another
subclass ready to support the @Resource annotations but I didn't
want to include it in this example since it doesn't demonstrate
anything different than the EJBAnnotationHelper subclass, and I'd
like to get some feedback first on the the technique. The general
technique, which we've discussed before, is pretty straightforward
and is summarized here for reference:
1 -- Discover the annotations: I had hoped that we could centralize
the discovery of annotations in the Deployer class prior to the
createModule phase of deployment, but as David Blevins pointed out
this is almost impossible. So it has to be pushed down into the
installModule phase of deployment after the necessary classloader
(s) and module context(s) have been established (see the changes
for AbstractWebModuleBuilder for an example).
2 -- Process the annotations: This just means to update the
existing deployment descriptor (or create a new one) with the
discovered annotations.
3 -- Set metadata-complete in the deployment descriptor to prevent
repeated processing of annotations (see the EjbRefBuilder changes
for an example)
4 -- Update the deployment descriptor in the module so that it can
flow through the remainder of the deployment process much as before
(for JNDI naming and resolution, and to remain with module in
support of the JSR-77 requirements for management).
Hey Tim, very clean and well documented code. I think we'll have to
strip out all the documentation to comply with Geronimo's strict no
javadoc policy ;)
Couple notes. We should be able to get rid of the @EJB for Web
processing in the EjbRefBuilder, no? That was there as temporary
hack and wasn't meant to last. You definitely have all the right
code in the EJBAnnotationHelper for Web/@EJB processsing.
Other note is you definitely want to construct the ClassFinder
exactly once for a module as each time it's constructed we'll have to
reparse all the class definitions in the entire module which is
especially nasty for web modules as there tend to be a lot of
libraries in WEB-INF/lib and WEB-INF/classes. I mention that as a
cautionary note as from the looks of where you're going each
AnnotationHelper would create it's own finder in it's constructor.
We may want to create the ClassFinder and pass it into the
AnnotationHelpers and/or put it in the Module somewhere for all to
use if they need it.
-David
--
Thanks,
Tim McConnell
