-1
I understand that the single file nature of this approach is considered attractive. JSR154 was considering supporting such descriptor extensions as part of the spec. However, this was removed from the spec and the feeling is that the J2EE jsrs will no longer favour such descriptor extensions (as was once going to be the case for all j2ee 1.4 descriptors).
The problems listed included:
+ difficulties in file lifecycles for tools that generate descriptors. Anything that does not know about geronimo would probably constantly overwrite any geronimo specific elements.
+ Difficulties in maintaining multi container deployment. Change control and generation of container specific configuration will be difficult if multiple tools want to add container specific information into the standards descriptors.
Jeremy Boynes wrote:
I have recently checked in a XML Schema for a couple of Geronimo-specific deployment descriptors. These rely on namespaces to allow vendor-specific elements to be included in standard deployment descriptors.
For example, an ejb-ref would be defined as: <ejb-ref> <ejb-ref-name>ejb/MyEJB</ejb-ref-name> <ejb-ref-type>Session</ejb-ref-type> <home>my.EJB.Home</home> <remote>my.EJB.Remote</remote> <ger:jndi-name>TestEJB</ger:jndi-name> </ejb-ref>
where ger: is the prefix for the Geronimo namespace.
The way this is intended to work is that the deployer will copy the standard deployment descriptor file to the Geronimo one and then add in out entries. If a geronimo descriptor exists, we will not use the standard one at all so developers will be able to work exclusively with the geronimo version. We will provide a tool for generating a standard descriptor by stripping out all geronimo-specific elements.
This is working for the application-client descriptor and we will be building out the EJB one once we know what the container-specific elements actually are.
This is a little different from the old-style form of vendor descriptors (e.g. as used by Weblogic or JBoss) where they were separate documents that contained just supplemental information. In light of this, I would appreciate feedback on the approach before we get too far along.
-- Jeremy
