With EJB 2.1, is declaring references to resources in ejb-jar.xml required?
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Published on 2009-10-28T14:11:32Z
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2010/06/17
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I'm using Weblogic 9.2 with a lot of MDBs. These MDBs access JDBC DataSources and write to both locally and externally managed JMS Destinations using local and foreign XAConnectionFactorys, respectively. Each MDB demarcates a container-managed JTA transaction that should be distributed amongst all of these resources.
Below is an excerpt from my ejb-jar.xml for an MDB that consumes from a local Queue called "MyDestination" and produces to an IBM Websphere MQ Queue called "MyOtherDestination". These logical names are linked to physical objects in my weblogic-ejb-jar.xml file.
Is it required to use the <resource-ref> and <message-destination-ref> tags to expose the ConnectionFactory and Queue to the MDB? If so, is it required by Weblogic or is it required by the J2EE spec? And for what purpose? For example, is it required to support XA transactionality?
I'm already aware of the benefit of decoupling the administered objects from my MDB using names exposed to the naming context of the MDB. Is this the only value added when specifying these tags? In other words, is it acceptable to just reference these objects from my MDB using the InitialContext and the objects' fully-qualified names?
<enterprise-bean>
<message-driven>
<ejb-name>MyMDB</ejb-name>
<ejb-class>com.mycompany.MyMessageDrivenBean</ejb-class>
<transaction-type>Container</transaction-type>
<message-destination-type>javax.jms.Queue</message-destination>
<message-destination-link>MyDestination</message-destination-link>
<resource-ref>
<res-ref-name>jms/myQCF</res-ref-name>
<res-type>javax.jms.XAConnectionFactory</res-type>
<res-auth>Container</res-auth>
</resource-ref>
<message-destination-ref>
<message-destination-ref-name>jms/myOtherDestination</message-destination-ref-name>
<message-destination-type>javax.jms.Queue</message-destination-type>
<message-destination-usage>Produces</message-destination-usage>
<message-destination-link>MyOtherDestination</message-destination-link>
</message-destination-ref>
</message-driven>
<enterprise-bean>
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