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From Dain Sundstrom <>
Subject Re: GERONIMO-2816 patch
Date Sat, 10 Feb 2007 22:27:17 GMT
Are you sure you must scan all classes in the web module for @EJB  
annotations?  I don't think it is necessary or what you want to do.   
I believe that you should only be checking specific classes for the  
annotation such as all known servlets.  This is how we process  
annotations for EJBs.  First we find all EJBs, either listed in the  
ejb-jar.xml or found by scanning for @Stateless, @Stateful and  
@MessageDriven.  Once we have the list of EJBs we check each class  
for the presence of the @EJB annotation.

In your case, I believe you are scanning for all classes that have  
the @EJB annotation which will be a much larger number of classes  
then just the servlets.  This over processing of classes can easily  
lead to naming conflicts.  Also, I do not believe that servlet 2.5  
has an @Servlet annotation, so I don't think you have to do any  
general purpose scanning like EJB module must do, which should make  
web deployment much more efficient.

Other than that, the patches look good :)  One minor thing to note is  
we don't use prefixes such as "m_" for variables.

Good job,


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).
>  --
> Thanks,
> Tim McConnell

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