JpaInjectionServices implementation is created three times?

[ljnelson]

I've found in my CDI SE application that much to my surprise my JPAInjectionServices implementation is created three times by AdditionalServiceLoader.  Is this by design?  If so, what design? :-)

Best,

Laird

[manovotn]

Hi Laird

I haven't really gone into code, but just looking at the javadoc you posted, it says - JpaInjectionServices is a per-module service.

So I would suppose your application has multiple modules and each of them loads it separately?

[ljnelson]

Thanks for your time.  I bet that's it.  I think I have more than three modules, but I can't swear to that, so I'll look there first.  Actually, see my next reply.

[ljnelson]

Actually, let me check that.  If I'm writing a CDI SE application consisting of several jar files with META-INF/beans.xml resources in them all on one classpath I should just have one big module, yes?  The javadocs for Deployment say:

For an application deployed in the SE environment, all library jars and classpath directories should be searched, and the bean deployment archive structure built. A single, logical deployment archive will be built for all beans and beans.xml files found on the classpath.

After debugging, I can see that there is:

• one Deployment with
• six BeanDeploymentArchives

This results in three ResourceLoaders that are used to find additional services.

Each ResourceLoader finds my JpaInjectionServices class.

I don't see a correlation between number of modules and instances of my JpaInjectionServices class.

It looks like for a CDI SE application, you will always end up with at least three ResourceLoaders used by getAdditionalServices():

1. one is the ClassLoaderResourceLoader used by the encompassing Deployment; it gets added to every BeanDeploymentArchive
2. two is the WeldClassLoaderResourceLoader.INSTANCE added always to the set of ResourceLoaders used by getAdditionalServices()
3. three is the DefaultResourceLoader.INSTANCE added always to the set of ResourceLoaders used by getAdditionalServices()

Each ResourceLoader will instantiate each Service it finds.  In my case, my JpaInjectionServices is instantiated three times.  Then when it is placed into the ServiceRegistry, only the first instance is kept and the remaining two are discarded, because shouldOverride() returns false (as it always will in this case).

So this has nothing to do with number of modules or archives, and in fact every Service implementation will be created three times in a CDI SE application.  That seems wrong, but I don't see an immediately obvious way to fix this.

[ljnelson]

I've created [WELD-2563] In a CDI SE application, three instances of every Service loaded are created; only one is used - JBoss Issue…  to track this.