Day: August 10, 2007

Hibernate: No Persistance Provider

While working through a code sample in Java Persistence with Hibernate, I ran into a problem where Hibernate was reporting No Persistence Provider. Solved the problem, and it wasn’t moving the persistence.xml file as you’d normally find on the web as the solution.

I’ve been spending a lot of time with Hibernate, an ORM persistence manager.

After ripping Pro Hibernate 3 a new one with a scathing review, I finally have concluded that the best book on Hibernate is Java Persistence with Hibernate, which is revised edition of Hibernate In Action, though you’ll still need to reference the ERRATA for Java Persistence with Hibernate on occasion.

In the middle of page 76 it was time to go build my sample application, and all I got was a strange message that said: javax.persistence.PersistenceException: No Persistence provider for EntityManager named helloworld


Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named helloworld
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)

Most of the discussions on the Web lead to the conclusion that the file persistence.xml is missing, or if it isn’t, it hasn’t been placed in the META-INF directory. In my case it was present, it was in the right place, and it was correct. What gives? Seems other people were having this problem as well.

The Solution
Thanks to a szermierz‘s entry on the introductory page An Introduction to Java Persistence for Client-Side Developers, which is actually a great article itself, it got me to question what libraries I had in my classpath, and whether or not that list was complete.

Turns out there was one file he listed that I didn’t have: hibernate-entitymanager.jar.

Looks important, eh?


I easily found a copy in the Hibernate Extensions at HibernateExt\tools\lib\testlibs.
There was also a copy in the Hibernate Tools at HibernateTools-3.2.0b9a\plugins\org.hibernate.exlipse_3.2.0.beta9a\lib\annotations.

Once I placed a copy in there, things worked great. So it’s not just the property file, but the .jar file that needs it.