I\'m setting up a standalone Java service with an in-process, in-memory HSQL database.
Persistence.xml
When I had this error, I realised that I was using the wrong provider class in persistence.xml
For Hibernate it should be
org.hibernate.ejb.HibernatePersistence
And for EclipseLink it should be
org.eclipse.persistence.jpa.PersistenceProvider
You should also note that different names are used in persistence.xml and when creating Persistence.createEntityManagerFactory("name")