It's actually caused by PersistenceProviderResolverPerClassLoader which is the default Resolver for PersistenceProviders.

You can easily get rid of this warning like this:

PersistenceProviderResolverHolder.setPersistenceProviderResolver(new PersistenceProviderResolver() {
private final List<PersistenceProvider> providers_ = asList((PersistenceProvider) new HibernatePersistenceProvider());

@Override
public List<PersistenceProvider> getPersistenceProviders()

@Override
public void clearCachedProviders() {

}
});