1. adding envers into org.hibernate module in as7, so user's app can see both hibernate and envers class (with an separate envers module i ran into some cycle dependency issue)

2. envers throws "listeners were not registed" exception, means hibernate's IntegratorServiceImpl can't see envers class/resource IntegratorServiceImpl is using java.util.ServiceLoader#load(Class<S> service), which internally using TCCL, (I think) that's the reason why core can't see envers' integrator. so, i created a custom ServiceLoader which use ClassLoaderService to find the integrator, but this doesn't work either. since, we need org.hibernate.service.classloading.internal.ClassLoaderServiceImpl#locateResources first (META-INF/services/org.hibernate.integrator.spi.Integrator) and ClassLoaderServiceImpl using resourceClassLoader to do this. by default, resourceClassLoader is set to applicationClassLoader in ClassLoaderServiceImpl. then, i changed IntegratorServiceImpl to use java.util.ServiceLoader#load(Class<S> service, IntegratorServiceImpl.class.getClassLoader() ), test pass, but this of course is not the fix. so, i changed the custom ServiceLoader to use classLoaderService to locateResources first, and using ServiceLoader.class.getClassLoader() to reload the resource again. here are the changes: https://github.com/stliu/hibernate-core/commit/09ce5defabea8cfb87d06c3d7b... https://github.com/stliu/jboss-as/commit/616237755626672157fb2ae565fadb16... thoughts?

I remember Scott and I discussing this exact issue. Unfortunately I do not remember the specifics. java.util.ServiceLoader#load(Class<S> service) does use the TCCL, but I think that the end result of our discussion was this is ok. We need to have this call be able to locate services both within the module classloader as well as within the classloader that ikncludes the user app. Scott, is there a single classloader that covers both of those cases that we could use?

On 06/16/2011 06:54 AM, Strong Liu wrote: > Hi there, > > first of all, I have finished this task, and test pass. > but :), i have to make the following changes, i'd like to hear you > guys' thoughts before i go to much away. > > 1. adding envers into org.hibernate module in as7, so user's app can > see both hibernate and envers class > (with an separate envers module i ran into some cycle dependency issue)

> > 2. envers throws "listeners were not registed" exception, means > hibernate's IntegratorServiceImpl can't see envers class/resource > > IntegratorServiceImpl is using java.util.ServiceLoader#load(Class<S> > service), which internally using TCCL, (I think) > that's the reason why core can't see envers' integrator. > > so, i created a custom ServiceLoader which use ClassLoaderService to > find the integrator, but this doesn't work either. > since, we need > org.hibernate.service.classloading.internal.ClassLoaderServiceImpl#locateResources > first (META-INF/services/org.hibernate.integrator.spi.Integrator) and > ClassLoaderServiceImpl using resourceClassLoader to do this. > by default, resourceClassLoader is set to applicationClassLoader in > ClassLoaderServiceImpl. > > then, i changed IntegratorServiceImpl to use > java.util.ServiceLoader#load(Class<S> service, > IntegratorServiceImpl.class.getClassLoader() > ), test pass, but this of course is not the fix. > > so, i changed the custom ServiceLoader to use classLoaderService to > locateResources first, and using ServiceLoader.class.getClassLoader() > to reload the resource again. > > here are the changes: > https://github.com/stliu/hibernate-core/commit/09ce5defabea8cfb87d06c3d7b... > > https://github.com/stliu/jboss-as/commit/616237755626672157fb2ae565fadb16... > > > thoughts? > > ----------- > Strong Liu&lt;stliu(a)hibernate.org&gt; > http://hibernate.org > http://github.com/stliu >

and adding envers into org.hibernate module, means there will no org.hibernate.envers module, and a (jpa) app's classloader can access org.hibernate module, right? so it can access envers class too.

> > and adding envers into org.hibernate module, means there will no org.hibernate.envers module, and a (jpa) app's classloader can access org.hibernate module, right? so it can access envers class too. Wrong, just adding envers to org.hibernate (either via a module dependency or the jar directly) doesn't result in envers being exported from the org.hibernate module. There is an option to do that, if so desired (via the export="true"). The better option is knowing whether or not it is needed and dynamically injecting envers only if it is.

From what you previously said, I think the dependencies are: - Application classes may reference the envers annotation. - Application classes may reference Hibernate classes. - Hibernate core may reference envers. - Hibernate envers may reference Hibernate core. Sound right so far?

As a follow-up, I tried adding Envers to a web application deployed on AS7 today, using Hibernate provided with the AS. I got some class loading problems though with dom4j. See the forum discussion: http://community.jboss.org/message/618823#618823 I also tried creating a separate Envers module which would depend on org.hibernate, but the Hibernate doesn't seem to see the Envers Integrator. Strong Liu: isn't it something you've prepared a patch for? I don't think it was included? Adam On Jun 21, 2011, at 8:23 AM, Adam Warski wrote: > > On Jun 20, 2011, at 7:56 PM, Scott Marlow wrote: > >>> >>> and adding envers into org.hibernate module, means there will no org.hibernate.envers module, and a (jpa) app's classloader can access org.hibernate module, right? so it can access envers class too. >> >> Wrong, just adding envers to org.hibernate (either via a module dependency or the jar directly) doesn't result in envers being exported from the org.hibernate module. There is an option to do that, if so desired (via the export="true"). The better option is knowing whether or not it is needed and dynamically injecting envers only if it is. > > Not sure how it works exactly, but I suppose that if the application declares somehow that it uses Envers, only then the Envers module should be visible? Looking at the dependencies tree between Hibernate modules, Envers is a leaf, so in theory it should be doable ;). > >> From what you previously said, I think the dependencies are: >> >> - Application classes may reference the envers annotation. >> >> - Application classes may reference Hibernate classes. >> >> - Hibernate core may reference envers. >> >> - Hibernate envers may reference Hibernate core. >> >> Sound right so far? > > Well Core doesn't reference Envers in any way. > > Envers aside, I think the Integrators should work anyway. Say a user creates his own Integrator and puts it as part of the application classes - will Hibernate see it on startup? The same applies to Envers - Hibernate should see the integrator if the module is enabled. > > -- > Adam Warski > > http://twitter.com/#!/adamwarski > http://www.warski.org > http://www.softwaremill.eu > > > > > > > > _______________________________________________ > hibernate-dev mailing list > hibernate-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/hibernate-dev