[hibernate-dev] hibernate-osgi JPA bootstrap & classloader

[Steve Ebersole]

I would fully expect hibernate-osgi to not directly use Bootstrap to build
an EntityManagerFactoryBuilder.  Bootstrap is geared toward users wanting
to leverage 2-phase JPA bootstrapping, not our components.  I would have
expected Enterprise OSGi support to instead directly build (and possibly
override) EntityManagerFactoryBuilderImpl.  I'll add that as a task for
post-5.0.  Because I think that is a first step in being able to better
manage bundles coming and going.  Please correct me if I am wrong.  Also
I'd like to start making sure that we fully support (certain) OSGi services
being replaced.  Especially thinking of TransactionManagers and DataSources.


On Tue, May 26, 2015 at 10:44 AM, Brett Meyer <brmeyer at redhat.com> wrote:

> IIRC:
>
> OsgiPersistenceProvider and OsgiSessionFactoryService both need *some* way
> to build the OsgiClassLoader and pass it into Hibernate bootstrapping.  For
> the SF, that's easy: just hand OSGiClassLoaderServiceImpl to
> BootstrapServiceRegistryBuilder.  For EMF, it looks like I mistakenly
> overrode those Bootstrap methods -- I missed that PersistenceUnitDescriptor
> included the CL.  So you're probably right -- presumably you could strip
> 'em out and somehow use the descriptor, but you might still need the
> overridden method in HibernatePersistenceProvider so that
> OsgiPersistenceProvider can give you the OsgiClassLoader to use.
>
> > Additionally, this ClassLoader is ultimately just used to build the
> > ClassLoaderService which hibernate-osgi overrides anyway.
>
> Right, assuming you're talking about
> 'ClassLoaderHelper.overridenClassLoader'.  But the intention there was to
> remove that whole class ASAP -- that was just a temporary hack for ORM 4,
> since CL handling was still really static.  But admittedly, I'm a bit out
> of touch with ORM 5, so I'm not sure if that's feasible yet.
>
> ----- Original Message -----
> > From: "Steve Ebersole" <steve at hibernate.org>
> > To: "hibernate-dev" <hibernate-dev at lists.jboss.org>
> > Sent: Saturday, May 23, 2015 1:49:50 PM
> > Subject: [hibernate-dev] hibernate-osgi JPA bootstrap & classloader
> >
> > Brett,
> >
> > As part of HHH-7527 (Enterprise OSGi support) you had changed
> > the org.hibernate.jpa.boot.spi.Bootstrap contract to basically overload
> > each method to additional accept a "providedClassLoader".
> >
> > Every one of those methods however, also accepts
> > a org.hibernate.jpa.boot.spi.PersistenceUnitDescriptor which exposes 2
> > ClassLoader already.
> >
> > Additionally, this ClassLoader is ultimately just used to build the
> > ClassLoaderService which hibernate-osgi overrides anyway.
> >
> > Just curious if I missed something.  Unless I did, it seems to me that we
> > really do not need these overloads on Bootstrap to support Enterprise
> > OSGi.  This dove-tails with a discussion from the Karaf user list
> > ultimately discussing OsgiClassLoaderService and "holding bundles" that
> are
> > being re-installed or upgraded.  Ultimately I am thinking through ways to
> > support being able to release OSGI bundle references from the
> > OsgiClassLoaderService...
> > _______________________________________________
> > hibernate-dev mailing list
> > hibernate-dev at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> >
>