java - EntityManager JNDI Lookup

Question

What is the correct JNDI string to look up this persistence unit JPA-DB that is shown on JBoss 6 Startup here:

10:26:09,847 INFO  [PersistenceUnitDeployment] Starting persistence unit persistence.unit:unitName=tpar.ear/tpar-jboss-ejb3.jar#JPA-DB
10:26:09,847 INFO  [Ejb3Configuration] Processing PersistenceUnitInfo [
        name: JPA-DB
        ...]        
10:26:09,847 WARN  [Ejb3Configuration] Persistence provider caller does not implement the EJB3 spec correctly.PersistenceUnitInfo.getNewTempClassLoader() is null.
...
...
10:26:10,950 INFO  [NamingHelper] JNDI InitialContext properties:{java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory, java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces}
10:26:10,950 INFO  [NamingHelper] Creating subcontext: persistence.unit:unitName=tpar.ear
10:26:10,950 INFO  [SessionFactoryObjectFactory] Bound factory to JNDI name: persistence.unit:unitName=tpar.ear/tpar-jboss-ejb3.jar#JPA-DB
10:26:10,950 INFO  [NamingHelper] JNDI InitialContext properties:{java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory, java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces}        

I have tried the following and various others that I don't remember now and they all throw the NameNotFoundException:

entityManager = (EntityManager) jndi.lookup("java:/EntityManagers/JPA-DB");
entityManager = (EntityManager) jndi.lookup("java:comp/EntityManagers/JPA-DB");
entityManager = (EntityManager) jndi.lookup("java:comp/env/JPA-DB");
entityManager = (EntityManager) jndi.lookup("JPA-DB");

question from:https://stackoverflow.com/questions/65907266/entitymanager-jndi-lookup

Answer 1

I was able to find the name by looking at the JNDI Tree view:

1. Go to http://localhost:8080/jmx-console
2. Search for JNDIView and click the link service=JNDIView
3. Invoke button for the list() method.
4. Search for the persistence name on the result tree view.

It looks like this:

Global JNDI Namespace

+- persistence.unit:unitName=tpar.ear (class: org.jnp.interfaces.NamingContext)
  |   +- tpar-jboss-ejb3.jar#JPADB (class: org.hibernate.impl.SessionFactoryImpl)

Though, the object is actually a SessionFactoryImpl and not an EntityManager. Additionally, the jndi lookup string generated by JBoss is hideous:

jndi.lookup("persistence.unit:unitName=tpar.ear/tpar-jboss-ejb3.jar#JPADB");

By adding the following property to the persistence.xml, I can look up using a shorter name while getting the object as an EntityManager at the same time:

<property name="jboss.entity.manager.jndi.name" value="tpar/entity-manager"/>

Note that using the long JNDI name still returns SessionFactoryImpl object in case anyone wants a SessionFactory.