[jboss-user] [EJB 3.0] - Re: Same datasource in multiple ear applications

[ALRubinger]

Yep; you can see the entry for your persistence.xml name in the JMX Console under the heading "persistence.units"...

As far as repackaging - you have a couple options:

Deployment Isolation - Every archive into your deploy directory exists in its own little bubble with its own classloader.  Classes in one application won't be available to another.  

Flat Deployment - All archives in your deploy directory use a shared classloader, making classes deployed from one app available to another.  The drawback here is in a classloader's "first one loaded wins" principle, and you won't be able to support different versions of the same package - plus it's VERY hard to debug.  For instance, assuming you have your 2 WARs, each one containing different versions of the Seam libraries.  You might start to see in one of the WARs unexpected results in the form of MethodNotFoundExceptions or worse - different behaviour than when deployed on its own.  You have to be very careful about not overlapping versions of classes when using flat deployment.

These articles explain it much better and in greater detail than I'm capable:

http://wiki.jboss.org/wiki/Wiki.jsp?page=ClassLoadingConfiguration
http://wiki.jboss.org/wiki/Wiki.jsp?page=JBossClassLoadingUseCases

Also, JBoss supports "Russian Doll" packaging, where any type of archive can be packaged into any other type of archive (eg. a WAR in an EAR in a JAR)...so as long as your aware of where your classes are, where they'll be available; the details are up to you.

S,
ALR

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3968248#3968248

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3968248