Chapter 8. Introduction to specifying dependencies in EJB3 beans

Dependencies of an EJB on a service or services, including other EJBs, may be specified through the <depends> tag of the jboss.xml deployment descriptor. The <depends> tag is analagous to the @org.jboss.ejb3.annotation.Depends annotation. The dependencies control the deployment of EJBs such that an EJB will not deploy until all of it's dependencies have successfully deployed.

jboss-service.xml :

Take a look at META-INF/jboss-service.xml. This service deployment descriptor starts a service based on org.jboss.tutorial.dependency.bean.DependedOn.

				
<server>
   <mbean code="org.jboss.tutorial.dependency.bean.DependedOn" name="jboss.test:service=DependedOn"/>
</server>

jboss.xml :

Take a look at META-INF/jboss.xml. This deployment descriptor indicates that the HasXmlMBeanDependencyBean is dependent on the jboss.test:service=DependedOn started by jboss-service.xml. The HasXmlMBeanDependencyBean will not deploy until the jboss.test:service=DependedOn service has successfully started.

Building and Running

Note

To build and run the example, make sure you have installed JBoss 5.x. See the Section 1.1, “JBoss Application Server 5.x” for details.

From the command prompt, move to the "dependency" folder under the Section 1.3, “Set the EJB3_TUTORIAL_HOME”

Ant Users:

Make sure your JBossAS-5.x is running

			
$ ant
$ ant run

run:
     [java] Lookup and bean access succeeded

Maven Users: Make sure the AS is not running.

$ mvn clean install -PRunSingleTutorial