There's the jboss.xml (for ejb jar files) where you can add dependencies per bean (i.e. a bean can be configured to depend on something else through the use of <depends>). But since you mention that it's the persistence.xml which requires this datasource, then you can just add this dependency in your persistence.xml. See this http://www.jboss.org/file-access/default/members/jbossejb3/freezone/docs/reference/1.0.7/html/entityconfig.html which explains about:

jboss.depends.{some arbitrary name} - Specify an MBean dependency for the persistence unit deployment. 

So you can use:

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
   http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
   version="1.0">
   <persistence-unit name="...">
      <jta-data-source>java:/DefaultDS</jta-data-source>
      ...
      <properties>
            ... 
          <property name="jboss.depends.1" value="jboss.test:service=YetAnotherDependedOn"/>
      </properties>
   </persistence-unit>
</persistence>

henk53 wrote:

 

 

Wouldn't it btw be possible for JBoss AS to spot the dependency automatically? If persistence.xml declares using a specific datasource and JBoss AS is able to keep track of which datasources are already deployed...

 

Would something like that be possible?

It does try to add a implicit dependency actually (AFAIK). And the document that i pointed to http://www.jboss.org/file-access/default/members/jbossejb3/freezone/docs/reference/1.0.7/html/entityconfig.html talks about a jboss.no.implicit.datasource.dependency property to "disable" this behaviour. The property description is as follows:

jboss.no.implicit.datasource.dependency - JBoss tries to register deployment dependencies for datasource by 
guessing the dependency name based on the jndi name of the datasource. Use this switch if the guess is wrong. 

I think the persistence module is not able to "guess" the datasource dependency MBean ObjectName correctly because you have packaged the -ds.xml within your .ear - which i think results in a different MBean ObjectName than if you had deployed it directly in deploy folder.