Re: [hibernate-dev] Proxies and typing
BTW, I did go back and verify that indeed the mismatch is with
@Proxy.proxyClass specifying an interface. Consider an example:
@Entity
@Proxy(proxyClass=User.class)
public class UserImpl implements User {
...
}
You will never be able to cast proxies instance of this thing to
UserImpl. This call will fail with CCE:
UserImpl u = (UserImpl) session.load( UserImpl.class, ... )
get() may or may not work depending.
This is the source of us not being able to offer generic signatures.
On Wed 25 Jan 2012 01:33:14 PM CST, Steve Ebersole wrote:
In regards to the new "load access", a user asked why we
don't
leverage generics.
The problem is the existence of @Proxy#proxyClass. We have the same
issue with Session#load/get taking the entity Class. We can't use a
generic sig like:
public <T> T load(Class<T> entityType, ...)
because at times we return objects that are not typed to <T>. I have
to dive back into the specifics, but IIRC the problem is that we don't
do the expected thing and have the generated proxy class extend from
the entity class if @Proxy#proxyClass names an interface. I remember
this change way back when, but the specifics of why escape me at the
moment.
IMO I think providing generic signatures would obviously be a great
improvement. Is it enough to change this behavior?
WDYT?
--
steve(a)hibernate.org
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