Question

I have a problem when I try to instantiate Hibernate and connect with a MySQL database (see error message below).

Curiously enough the connection works fine using the exact same hibernate.cfg.xml file when running Junit tests but it refuses to work when run from Tomcat…

I am starting to run out of ideas.

Any clues or tip where to look?

Caused by: org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.DynamicMapEntityTuplizer]
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:110)
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructDefaultTuplizer(EntityTuplizerFactory.java:135)
at org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping.(EntityEntityModeToTuplizerMapping.java:69)
at org.hibernate.tuple.entity.EntityMetamodel.(EntityMetamodel.java:323)
at org.hibernate.persister.entity.AbstractEntityPersister.(AbstractEntityPersister.java:456)
at org.hibernate.persister.entity.SingleTableEntityPersister.(SingleTableEntityPersister.java:131)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:84)
at org.hibernate.impl.SessionFactoryImpl.(SessionFactoryImpl.java:267)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1341)
at se.fmt.atlantism.util.HibernateUtil.buildSessionFactory(HibernateUtil.java:16)
… 38 more
Caused by: java.lang.NullPointerException
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:107)
… 47 more

Answer 1

I’m writing this for future Googlers and reference.

I’ve done some more research and the root source of the problem is still not known. However the following article throw me on the right track.

http://www.howtogeek.com/howto/linux/installing-tomcat-6-on-ubuntu/

It seems like the Tomcat (version 6 at least) packages available in Ubuntu (and Debian) are not working correctly. Instead I installed Tomcat using the following guide:

http://www.ctrip.ufl.edu/tomcat6-debian-lenny-howto

While this might not be the premium choice of installation it seems necessary to get Tomcat version 6 running without problems on Ubuntu and/or Debian Lenny.