[hibernate-dev] Entity name in the context of JPA2 meta model (HHH-5709).

Tomasz Blachowicz tblachowicz at gmail.com
Wed Nov 3 09:54:09 EDT 2010 

I think I understand what you mean. "Node name" might not be indeed the best
way to do that.

I think implementation of the EntityBinder with regards to the handling of
@Entity.name is correct. My understanding of the jsr-317 is that the entity
name used in queries should be @Entity.name if specified otherwise the
default value that is unqualified name of the entity class. This is how
EntityBinder works now I presume (EntityBinder#bindEjb3Annotation(@Entity)).
The think is that this value is set to the name field of EntityBinder and
then used to set PresistentClass#setNodeName().

I wonder how I could implement the meta model change to make sure the
EntityType#getName() returns @Entity.name or unqualified class name in case
the @Entity.name has not been specified. How about adding new property to
the PersistentClass that would hot the value as computed in EntityBinder and
the I could use the value of this property to populate EntityTypeImpl from
MetamodelImpl#buildEntityType? Can you comment that approach?

On Wed, Nov 3, 2010 at 1:22 PM, Steve Ebersole <steve at hibernate.org> wrote:

> Ah, I misread.  I thought you meant the Hibernate notion of an "entity
> name".
> As far as I can tell now looking at it, there is no such annotation equiv
> for
> that.
>
> @javax.persistence.Entity.name is really more akin to Hibernate's notion
> of an
> import name for queries.
>
> I am not really understanding the benefit of returning the query import
> name
> for EntityType.getName().  Personally I think its just a case of badly
> matched
> attribute names and an inference being drawn there.
>
> But we do not really use that internally, so i have no qualms with changing
> it
> I guess.  However, I do not want "node name" used.  That is a totally
> different beast, and if annotations ever support alternate entity modes
> this
> will become a problem in this code you suggest; its currently working just
> by
> a quirk where the default node name just happens to be the unqualified
> entity
> name, and I am assuming the annotation binding code is setting it if
> @Entity.name is specified as well.  To be honest, after looking at
> org.hibernate.cfg.annotations.EntityBinder#bindEntity my first thought was
> whether this code even handles @Entity.name properly in terms of making it
> an
> import name.  It would work as is for the default case because that is
> Hibernate's internal default behavior (to register the unqualified entity
> name
> as an import name).
>
>
> On Wednesday, November 03, 2010, at 07:58 am, Steve Ebersole wrote:
> > If that is really the case, then that is a problem with the annotation
> > binding code.
> >
> > On Wednesday, November 03, 2010, at 06:50 am, Tomasz Blachowicz wrote:
> > > Hi Steve,
> > >
> > > PersistentClass#getEntityName is not good, because it is exactly the
> same
> > > value as PersistentClass#getClassName.
> > > PersistentClass#getClassName is populated in
> > > org.hibernate.cfg.annotations.EntityBinder#bindEntity with the value
> from
> > > org.hibernate.annotations.common.reflection.java.JavaXClass#getName.
> > > JavaXClass#getName is implemented as clazz.getName(), so it is always
> > > class name and the @Entity.name is simply ignored for the purpose of
> the
> > > entity name. And this is the reason I used PersistentClass#getNodeName
> > > that returns @Entity.name or "unqualified" class name in case
> > > @Entity.name is unspecified.
> > >
> > > If I'd stick with PersistentClass#getEntityName the issues is not
> > > resolved and EntityType.getName() returns stil FQN of the class instead
> > > of @Entity.name or "unqualified" class name.
> > >
> > > Regards,
> > > Tom
> > >
> > > On Wed, Nov 3, 2010 at 11:12 AM, Steve Ebersole <steve at hibernate.org>
> wrote:
> > > > Uncertain yet of how these pull request comments work on GitHub, so I
> > > > thought
> > > > I'll make sure and respond here.  The change should use
> > > > org.hibernate.mapping.PersistentClass#getEntityName instead of
> > > > org.hibernate.mapping.PersistentClass#getNodeName.
> > > >
> > > > See my other email to the dev list about porting to 3.6
> > > >
> > > > On Wednesday, November 03, 2010, at 05:48 am, Tomasz Blachowicz
> wrote:
> > > > > I've submitted the pull request (
> > > > > https://github.com/hibernate/hibernate-core/pull/8) for master. I
> > > > > should have it also ready for 3.6 branch as soon as I manage to
> merge
> > > > > the change between branches in this git thng that is pretty new to
> me
> > > > > ;)
> > > > >
> > > > > On Tue, Nov 2, 2010 at 1:18 PM, Emmanuel Bernard
> > > >
> > > > <emmanuel at hibernate.org>wrote:
> > > > > > Cool :)
> > > > > > If you use GitHub's infrastructure and use a pull-request, we can
> > > > > > get that integrated quite fast.
> > > > > >
> > > > > > On 2 nov. 2010, at 13:50, Tomasz Blachowicz wrote:
> > > > > >
> > > > > > I've already created the ticket (
> > > > > >
> http://opensource.atlassian.com/projects/hibernate/browse/HHH-5709)
> > > > > > . And I should be able to create the patch sometime this evening.
> > > > > >
> > > > > > Cheers,
> > > > > > Tom
> > > > > >
> > > > > > On Tue, Nov 2, 2010 at 12:24 PM, Emmanuel Bernard
> > > >
> > > > <emmanuel at hibernate.org>wrote:
> > > > > >> I'd say you're correct and the name should match in the
> metamodel.
> > > > > >> Can you open a JIRA issue and even better try and work out a
> > > > > >> patch?
> > > > > >>
> > > > > >> PS: I've spilled hot chocolate on my laptop in the past: not
> good,
> > > > > >> the machine slowly but inevitably dies as corrosion wins it
> over.
> > > > > >>
> > > > > >> On 2 nov. 2010, at 12:35, Tomasz Blachowicz wrote:
> > > > > >> > Hi,
> > > > > >> >
> > > > > >> > I had been working recently on some stuff that deals with JPA2
> > > > > >> > meta
> > > > > >>
> > > > > >> model.
> > > > > >>
> > > > > >> > Hibernate is my JPA2 provider/engine. Everything works fine
> > > > > >> > except
> > > >
> > > > one
> > > >
> > > > > >> > little thing that is name of the Entity. I'd expect that value
> > > > > >> > returned
> > > > > >>
> > > > > >> by
> > > > > >>
> > > > > >> > EntityType.getName() would be the same as @Entity.name but not
> > > > > >> > the
> > > >
> > > > FQN
> > > >
> > > > > >> of
> > > > > >>
> > > > > >> > the entity class. Although this is not explicitly stated in
> the
> > > > > >> > JPA2 specification it is reasonable to expect that
> @Entity.name
> > > > > >> > or the
> > > > > >>
> > > > > >> default
> > > > > >>
> > > > > >> > value (shortened class name) is the name of the entity used in
> > > >
> > > > queries
> > > >
> > > > > >> ans
> > > > > >>
> > > > > >> > well as other places such as meta model. I know the topic of
> > > > > >> > entity name
> > > > > >>
> > > > > >> was
> > > > > >>
> > > > > >> > discussed  many times in the past (HHH-2597, HHH-4375,
> HHH-4465,
> > > > > >>
> > > > > >> HHH-5709),
> > > > > >>
> > > > > >> > and the rationale has been given for current implementation of
> > > > > >>
> > > > > >> Hibernate,
> > > > > >>
> > > > > >> > however the topic hasn't been touched in the context of meta
> > > > > >> > model that
> > > > > >>
> > > > > >> is
> > > > > >>
> > > > > >> > new stuff added in JPA2.
> > > > > >> >
> > > > > >> > I just wanted to know what is your thinking with regards to
> the
> > > >
> > > > matter
> > > >
> > > > > >> at
> > > > > >>
> > > > > >> > this stage and how likely is implementation of Hibernate would
> > > >
> > > > change
> > > >
> > > > > >> > to match EntityType.getName with @Entity.name.
> > > > > >> >
> > > > > >> > P.S.
> > > > > >> > I just have spilled the entire cup of fresh coffee on my
> desktop
> > > >
> > > > while
> > > >
> > > > > >> > writing this message. The mouse seems to be drowned :|
> > > > > >> >
> > > > > >> > Cheers,
> > > > > >> > Tom
> > > > > >> > _______________________________________________
> > > > > >> > hibernate-dev mailing list
> > > > > >> > hibernate-dev at lists.jboss.org
> > > > > >> > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> > > > >
> > > > > _______________________________________________
> > > > > hibernate-dev mailing list
> > > > > hibernate-dev at lists.jboss.org
> > > > > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> > > >
> > > > ---
> > > > Steve Ebersole <steve at hibernate.org>
> > > > http://hibernate.org
> > > > _______________________________________________
> > > > hibernate-dev mailing list
> > > > hibernate-dev at lists.jboss.org
> > > > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> >
> > ---
> > Steve Ebersole <steve at hibernate.org>
> > http://hibernate.org
>
> ---
> Steve Ebersole <steve at hibernate.org>
> http://hibernate.org
> _______________________________________________
> hibernate-dev mailing list
> hibernate-dev at lists.jboss.org
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>

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