Injecting JMS Queue / Destination into MDB fails

Question

I am trying to inject a Destination into an EJB3 MDB using
    @Resource(name = "queue/abc/Responses")
    private Destination m_responseQueue;In the ejb-jar.xml file I declare the following
      <message-driven>
            <ejb-name>JobRequestListener</ejb-name>
            <ejb-class>com.abc.backend.jobs.JobRequestListener</ejb-class>
            <message-destination-link>JobRequests</message-destination-link>
            <!--Inherited From AbstractManagedBean -->
            <resource-ref>
                <res-ref-name>jms/ConnectionFactory</res-ref-name>
                <res-type>javax.jms.ConnectionFactory</res-type>
                <res-auth>Container</res-auth>
            </resource-ref>
            <!--Local Resources -->
            <message-destination-ref>
                <message-destination-ref-name>queue/abc/Responses</message-destination-ref-name>
                <message-destination-type>javax.jms.Queue</message-destination-type>
                <message-destination-usage>Produces</message-destination-usage>
                <message-destination-link>Responses</message-destination-link>
            </message-destination-ref>
        </message-driven>and in weblogic-ejb-jar.xml I add
    <weblogic-enterprise-bean>
        <ejb-name>JobRequestListener</ejb-name>
        <message-driven-descriptor>
            <pool>
                <max-beans-in-free-pool>20</max-beans-in-free-pool>
                <initial-beans-in-free-pool>10</initial-beans-in-free-pool>
            </pool>
            <destination-jndi-name>queue/abc/JobRequests</destination-jndi-name>
        </message-driven-descriptor>
        <transaction-descriptor>
            <trans-timeout-seconds>315</trans-timeout-seconds>
        </transaction-descriptor>
        <!--Inherited From AbstractManagedBean -->
        <resource-description>
            <res-ref-name>jms/ConnectionFactory</res-ref-name>
            <jndi-name>jms/ABCConnectionFactory</jndi-name>
        </resource-description>
        <!--Local Resources -->        
        <resource-description>
            <res-ref-name>queue/abc/Responses</res-ref-name>
            <jndi-name>queue/abc/Responses</jndi-name>
        </resource-description>
    </weblogic-enterprise-bean>Initially I didn't have the resource-description in the weblogic-ejb-jar.xml file, but even after adding it I am still getting the following exception during deployment
[EJB:011026]The EJB container failed while creating the java:/comp/env namespace for
this EJB deployment. weblogic.deployment.EnvironmentException:
[EJB:010176]The resource-env-ref 'queue/abc/Responses' declared in the ejb-jar.xml
descriptor or annotation has no JNDI name mapped to it. The resource-ref must
be mapped to a JNDI name using the resource-description element of the
weblogic-ejb-jar.xml descriptor or corresponding annotation.
     at weblogic.ejb.container.deployer.EnvironmentBuilder.addResourceEnvReferences(EnvironmentBuilder.java:639)
     at weblogic.ejb.container.deployer.EJBDeployer.setupEnvironmentContext(EJBDeployer.java:247)
     at weblogic.ejb.container.deployer.EJBDeployer.setupEnvironmentFor(EJBDeployer.java:1014)
     at weblogic.ejb.container.deployer.EJBDeployer.setupBeanInfos(EJBDeployer.java:908)
     at weblogic.ejb.container.deployer.EJBDeployer.prepare(EJBDeployer.java:1188)
     at weblogic.ejb.container.deployer.EJBModule.prepare(EJBModule.java:425)By injecting a Queue rather then a destination I can work around this issue, however I would prefer to use a Destination as this allows me to change the behavior of my application without making code changes. It seems like a bug in 10.3 to me.
Edited by: ejb3workshop on Sep 1, 2009 1:44 PM
Edited by: ejb3workshop on Sep 1, 2009 1:59 PM
Edited by: ejb3workshop on Sep 2, 2009 3:11 PM

Answer 1

Because JMS resources by the very nature are "undependable", I think it is usually not advisable to inject JMS resources into an EJB except for MDB source destinations. The problem with injection of JMS resources is that if the JMS resource is not available at the point the EJB is originally deployed/initialized, the EJB deployment/initializaition will fail (except for MDBs, which will still deploy if the source is down, and will automatically retry internally). This is goodness for many types of resources, but since JMS resources are not necessarily always available by their very nature (down for maintenance, in the middle of a migration, initializing later in the boot, etc), most messaging applications should be specifically designed to be robustly handle the failure case during runtime.
Anyhow, EJB3 does not require descriptors.
I haven't fully vetted the following samples, but I think they should be pretty close to correct.
Sample MDB code:
// MDB will still deploy even if the source destination is down (the container will keep retrying internally).
@MessageDriven(mappedName = "Server1Q1",
                        activationConfig = {@ActivationConfigProperty(
                                                      propertyName = "connectionFactoryJndiName",
                                                      propertyValue = "Server1CF")})
public class MyMDB implements MessageListener {
  @EJB
  private MyStateless myStateless;
  @TransactionAttribute(TransactionAttributeType.REQUIRED)
  public void onMessage(Message message) {
    System.out.println("Got the message, version 5: "+message);
    myStateless.completeWorkOrder();
Sample injected JMS resources - no resource descriptors needed:
@Stateless(mappedName="StatelessBean")
public class MyStatelessBean implements MyStateless {
  int ctr;
  @Resource(mappedName="mdbq2")
  private Queue queue1;
  @Resource(mappedName="cfadmin2")
  private QueueConnectionFactory connectionFactory2;
Sample pseudo-code for non-injected JMS resources, no resource descriptors needed:
Eg, instead of
@Resource(mappedName="cfadmin")
private QueueConnectionFactory cf;
Do this:
  // note the semi-colon!  turns off injection, note the type field -- required
  // I'm not sure of exact syntax
  //cfadmin is assumed to be the JNDI name if the
  // JNDI name isn't specified in another parameter... 
  @Resource(mappedName="cfadmin", type="javax.jms.QueueConnectionFactory");  
  // this is not injected now
  // cache cf for re-use (performance)
  private QueueConnectionFactory cf;
  @Resource
  private SessionContext sctx;  // inject the session ctx
And in the source code itself, do this:
   int tryCount == 3; 
   while (cf != null) {
     try { 
       // not quite sure if this is the righ syntax, but I think "java:/comp/env" prefix
       // isn't needed for the new EJB3.0 session context
       cf = sctx.lookup("cfadmin");  //cfadmin is mappedname for resource above
     } catch (NNN n) {  // don't know the exact exception
       if (--tryCount == 0) throw n;
       sleep 3 seconds  // don't want to retry in a tight loop
Tom