+1 (a) is the only feasible option
On Mon, Mar 5, 2018, 7:53 AM Sanne Grinovero <sa...@hibernate.org> wrote: > Issue HHH-12353 was just reported and I have to agree it looks dodgy. > > Essentially invoking: > > entityManager.getReference( Person.class ) > > might not return a type compatible with Person, when Person is final > and annotated with @Proxy(proxyClass = AnotherTypeX.class), then > AnotherTypeX might be returned and this is not necessarily a subtype > of Person. > > That's ok as I understand we hardly have alternatives, but the > EntityManager API for getReference mandates this signature: > > <T> T getReference(Class<T> entityClass, Object primaryKey) > > so we're not actually returning the expected type T in all > circumstances, confusing compilers and tooling into giving the wrong > suggestions. > > I see some options: > a# disallow using @Proxy on a final entity - seems reasonable since > the docs warn against pitfalls. > b# throw an exception on Person.class being used as parameter, as the > user should actually use the proxytype? > c# somehow have the proxy still extend the final entity? > > Option b# seems problematic as it's not obvious to users either, and > we would need to return a proxy reference even when there actually is > a managed Person instance in the current session. > > Option c# is probably unrealistic and problematic too, as it would > require enhancing of the final class and I guess we can't rely on that > consistently. > > In summary, I believe we should throw a bootstrap exception requiring > to remove the `final` modifier on the parent entity. Or challenge the > specification :( > > Thanks, > Sanne > _______________________________________________ > hibernate-dev mailing list > hibernate-dev@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/hibernate-dev > _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev
