Specify DataSource settings at the application level (in the .EAR)

At the moment you can specify application's DataSource settings either in the global JBoss configuration (standardjbosscmp-jdbc.xml) or in the EJB JAR (META-INF/jbosscmp-jdbc.xml). When developing EJB components that are re-used in many applications, it is frustrating to have to create a separate EJB JAR version for each application in order to be able to specify which DataSource to use for the EJB component. It would be much easier if the DataSource could be specified at the application level (in the EAR) because often all the application's EJB components use the same DataSource. In addition because the EJB JAR would no longer contain deployment specific settings, you could include the same EJB JAR file in all the application's EAR files.

I propose that this improvement is implemented by reading default settings also from the EAR's META-INF/jbosscmp-jdbc.xml. You could then specify a default configuration for each application and still override it inside the EJB JAR if necessary. I have implemented this functionality using the source code from version 4.0.4.GA. I will attach the necessary patches to this issue for your evaluation.