openjpa-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Thomas G Lawless <>
Subject OpenJPA and JAXB
Date Thu, 13 Aug 2009 19:30:30 GMT

I have been experimenting with OpenJPA and JAXB with regard to storing and
retrieving XML from an DB2 9.7 database and I've run into a problem.  I've
gone through the steps of creating a simple XML schema and generating the
Java classes using xjc.  I have followed the steps in the OpenJPA manual so
I have not defined a name space in the schema and I have added the
@XmlRootElement annotation to the generated root class.  I have created
sample code that successfully creates an instance of my entity with the
JAXB property and I can persist the entity to the database.  I can also
retrieve the entity from the database and the XML is unmarshalled
successfully as long as I use a single instance of the EntityManager to do
both tasks.  What I've found is if I use a separate instance on
EntityManager to retrieve the entity, I receive an error along the line of

javax.xml.bind.JAXBElement incompatible with.....

This only happens if I use a instance of EntityManager that is different
then the instance used to persist the original record.  For example, if I
do the following:

EntityManagerFactory emFactory = .......
EntityManager em = emFactory............
      Create the instance of the JAXB class and the entity.
      Populate both classes with data.
      Set the JAXB property of the entity class


MyEntity entity = em.find(.......);

The above code executes without error.  I've checked the db record and it
is correct.  I have also validated the XML in the db against the schema
used to generate the JAXB classes and there are no issues there either.  If
I run another program that tries to retrieve the same entity as above....

EntityManagerFactory emFactory = .......
EntityManager em = emFactory...........

MyEntity entity = em.find(.......);....

the exception noted above is thrown.  I am currently using OpenJPA 1.2.1
and JAXB 2.0.5.  I have also tried this with JAXB 2.1.12 and I receive the
same result.  Am I doing something wrong?  Could this be a bug in OpenJPA?
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message