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
this:
org.apache.openjpa.persistence.PersistenceException:
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............
em.getTransaction().begin();............
/*.
Create the instance of the JAXB class and the entity.
Populate both classes with data.
Set the JAXB property of the entity class
*/
em.persist(.....);
em.getTransaction().commit();
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....
i.e.
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?
