to answer my own question: It was not really connected to OpenJPA, the reason for that exception was a conflict between java-ee-5.1.2.jar and another jar that contains the javax.persistence.* packages. By modifying java-ee-5.1.2.jar to have only a single version of the javax.persistence.* packages in the classpath the issue was fixed.
Thanks, Sebastian 2011/12/9 seba.wag...@gmail.com <seba.wag...@gmail.com> > Hi, > > some users of (Apache) Openmeetings report following exception to our > mailing lists: > > *javax.persistence.PersistenceException: Found > 'javax.persistence.provider' property in the map but the value is not a > String. Found object : 'null'.* > > You can find hardly anything about this exception in the net and I tested > on various platforms ... never had this issue. > > Is there a known problem or root cause for this exception? > It seems to me like a problem with finding the persistence.xml. > > Thanks! > Sebastian > -- Sebastian Wagner http://www.openmeetings.de http://www.webbase-design.de http://www.wagner-sebastian.com seba.wag...@gmail.com
