Configuring an MDB to receive messages from ActiveMQ
There are three MDBs declared in the ejb-jar.xml deployment descriptor. For this example, I will be explaining how to configure the
TopicDurableMDB to be invoked by JBoss when a message is received on an ActiveMQ Topic.
In the ejb-jar.xml deployment descriptor, the
TopicDurableMDB is declared as follows:
activation-config element and it's child element,
activation-config-property, are new elements for EJBs, so you might not be familiar with them. I won't go into to much detail about them, but it is important to understand that this is the first mechanism you use to link an MDB to a JCA.
activation-config-properties shown above link to the following elements in the ra.xml file, which is contained within the activemq-ra-1.2.rar file:
In the ejb-jar.xml file section shown above, the value of the
Destination property is set to
topic.testTopic. This value is the physical name of the ActiveMQ destination the
TopicDurableMDB will be receiving messages from and not a JNDI name. In other words, the value of the
Destination property has no meaning to JBoss. It is purely an ActiveMQ setting.
In JBoss, the thing which connects an inbound JMS destination to an MDB is a JBoss container. To use ActiveMQ as the inbound message source for the
TopicDurableMDB we must configure a new JBoss container. We do this in the jboss.xml file.
Three things are needed in the jboss.xml file in order to tie an MDB to a connector. They are:
- Configure a new
invoker-proxy-binding that declares
JBossMessageEndpointFactory as the
- Configure a new MDB container which uses the new
- Declare which MDBs should go into the new container
This first snippet configures a new
This second snippet configures a new MDB container which uses the
invoker-proxy-binding configured above:
This third snippet links the
TopicDurableMDB to the activemq-ra-1.2.rar connector and tells JBoss to put instances of
TopicDurableMDB into the new MDB container declared above:
The above examples highlight the key configuration settings needed to enable MDBs deployed in JBoss to process messages from an ActiveMQ destination.
You can try the above example, plus a few more, by downloading the activemq-jboss-test.zip file which contains the complete sample project.