RollbackException; internal toplink error.

Question

All -
I'm slightly new to JPA so far I have found it to be great with the exception of one problem.
I'm getting the following error after calling em.commit(), the stack stack is as follows:
javax.persistence.RollbackException: java.lang.NullPointerException
     at oracle.toplink.essentials.internal.ejb.cmp3.transaction.base.EntityTransactionImpl.commit(EntityTransactionImpl.java:105)
     at oracle.toplink.essentials.internal.ejb.cmp3.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:45)
Caused by: java.lang.NullPointerException
     at oracle.toplink.essentials.internal.descriptors.MethodAttributeAccessor.getAttributeValueFromObject(MethodAttributeAccessor.java:86)
     at oracle.toplink.essentials.mappings.DatabaseMapping.getAttributeValueFromObject(DatabaseMapping.java:357)
     at oracle.toplink.essentials.mappings.foundation.AbstractDirectMapping.compareObjects(AbstractDirectMapping.java:250)
     at oracle.toplink.essentials.mappings.foundation.AbstractDirectMapping.compareForChange(AbstractDirectMapping.java:219)
The data is persisted yet seeing this internal exception is worry some any and all help would be much appreciated.
Thanks,
..Chris

Answer 1

Hi Chris -
So it turns out the problem I was having with the NPE still exists, I did not see it in my second implementation because it was incomplete compared to when I did it the first time.
The problem comes up when working with @Embeddable and @Embedded annotations. I have placed the @Embeddable annotation on the class that I would like to exist in the same database table as another one of my entities, this embedded object exists in it's one java file. In my entity I have annotated the 'getter' for this object with the @Embedded annotation.
Using the debugger and stepping through the code several times I cant find anything in any of my objects thats null, I have even added asserts to all the getters and setters.
Any help, tips would be great.
Regards,
..Chris