[eclipselink-users] Abstract @Entities, non-abstract subclasses

[Laird Nelson <ljnelson@xxxxxxxxx>]

I have a case that is handled just fine by both Hibernate and OpenJPA (their JPA 2.0 implementations) and cannot be handled by EclipseLink 2.0.0.

I have an abstract @Entity class.

Then I have two concrete subclasses that are not defined as entities and do not add any state (they just override behavior).

I am running this scenario in a non-Java-EE environment.

EclipseLink barfs on EntityManagerFactory initialization, claiming that some class does not have a public no-argument constructor, which is false.  Here is the stack trace:

Local Exception Stack: 
Exception [EclipseLink-34] (Eclipse Persistence Services - 2.0.0.v20091127-r5931): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: This class does not define a public default constructor, or the constructor raised an exception.
Internal Exception: java.lang.InstantiationException
Descriptor: RelationalDescriptor(com.jenzabar.ngp.identity.jpa.AbstractPassiveReference --> [DatabaseTable(reference)])
    at org.eclipse.persistence.exceptions.DescriptorException.instantiationWhileConstructorInstantiation(DescriptorException.java:724)
    at org.eclipse.persistence.internal.descriptors.InstantiationPolicy.buildNewInstanceUsingDefaultConstructor(InstantiationPolicy.java:139)
    at org.eclipse.persistence.internal.descriptors.InstantiationPolicy.buildNewInstance(InstantiationPolicy.java:103)
    at org.eclipse.persistence.descriptors.ClassDescriptor.selfValidationAfterInitialization(ClassDescriptor.java:3519)
    at org.eclipse.persistence.descriptors.ClassDescriptor.validateAfterInitialization(ClassDescriptor.java:5247)
    at org.eclipse.persistence.descriptors.ClassDescriptor.postInitialize(ClassDescriptor.java:3241)
    at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:463)
    at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:406)
    at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.postConnectDatasource(DatabaseSessionImpl.java:671)
    at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.login(DatabaseSessionImpl.java:633)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:230)
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:368)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.getServerSession(EntityManagerFactoryImpl.java:151)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:207)
    at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:195)

What is happening here?

The JPA 2.0 specification says--explicitly--that entities may be abstract, and their subclasses may be concrete, so I would expect that this case should work.

Thanks,
Laird