[hibernate-dev] EntityManagetFactory unwrap - HHH-9665

Hi there, Steve and I are having a discussion around the intended behavior of EntityManagerFactory#unwrap. See also HHH-9665[1] and the corresponding pull request [2]. At the moment the implementation in EntityManagerFactoryImpl allows to unwrap into the implementation class itself. This way the user gets a reference to an internal class. IMO there should be instead a public interface which the user can unwrap to, eg HibernateEntityManagerFactory. This interface hosts additional methods we want to expose on top of the HibernateEntityManagerFactory. The unwrapping to should be disallowed (by expception) in this case. IMO this is just a continuation of the whole idea of splitting packages between public, spi and internal. Of course this cannot stop a user from doing an explicit cast, but that's a different story imo. Steve and I have different take on this issue, so we where wondering what others think? --Hardy [1] https://hibernate.atlassian.net/browse/HHH-9665 [2] https://github.com/hibernate/hibernate-orm/pull/911