[javaee-spec users] Re: [jpa-spec users] JPA_SPEC-145, JPA_SPEC-146: Provide support for JDK9 module system

From: Werner Keil <>
Date: Wed, 3 May 2017 18:24:25 +0200


Thanks for bringing that up.

I was wondering, if there is a common pattern all (Java EE) JSRs are
supposed to follow for making the JSRs Java 9/Jigsaw compatible?

and JSON-P

already got a module-info (at least for JSR 374 it was also you who created
or last changed it;-)

Based on module naming by the JDK itself, should we take
"java.<something>" as a module name to be the preferred name for both the
JDK and all JSRs under

Or are there other preferences e.g. "javax.<something>" to match the Maven
GroupId of most Java EE JSRs especially those by Oracle?
see for JSR 374.

A former EG Member of JSR 363 also asked this in our list and we discussed
what would be a good module name there, but wanted to wait for official JCP
guidance if possible.

Thanks and Regards,

On Wed, May 3, 2017 at 6:13 PM, Lukas Jungmann <>

> Hi,
> Since the release of JDK 9 is behind the corner, it would be good to
> update the spec to be ready for it.
> I can see 2 things which can be done:
> 1) JPA_SPEC-145: define module name
> I'm not 100% sure this needs to be done but for the sake of completeness -
> it is clear that the module name should be 'java.persistence'. While it
> would be nice to have the name defined and available, do we really need
> this or should we stick with API being resolved on JDK9 as an automatic
> module?
> I'm proposing to NOT touch this area in the spec now and keep this up to
> the provider. Any opinions?
> 2) JPA_SPEC-146: Use ServiceLoader facility
> with the introduction of the module system there are currently 2 ways, how
> persistence provider implementation can be defined - META-INF/services and
> module-info with 'provides ... with...'. Former way is already covered but
> the latter is not, so I'd like to propose following change to Section 9.2
> of the spec (additions are in italics, removals are striked-through italics)
> *Section 9.2 Bootstrapping in Java SE Environments*
> In Java SE environments, the Persistence.createEntityManagerFactory
> method is used
> by the application to create an entity manager factory.
> A persistence provider implementation running in a Java SE environment
> should also act as a service
> provider by supplying a service provider configuration *file as described
> in the JAR File Specification*. *The Persistence*
> *bootstrap class should use ServiceLoader facility to locate all available
> provider implementations.*
> The provider configuration *file* serves to export the provider
> implementation class to the Persistence
> bootstrap class, positioning the provider as a candidate for backing named
> persistence units.
> The provider may supply the provider configuration file by creating a text
> file named javax.persistence.spi.PersistenceProvider
> and placing it in the META-INF/services directory of
> one of its JAR files. The contents of the file should be the name of the
> provider implementation class of
> the javax.persistence.spi.PersistenceProvider interface.
> Example* 1*:
> A persistence vendor called ACME persistence products ships a JAR called
> acme.jar that contains
> its persistence provider implementation. The JAR includes the provider
> configuration file.
> acme.jar
> META-INF/services/javax.persistence.spi.PersistenceProvider
> com.acme.PersistenceProvider
> …
> The contents of the META-INF/services/javax.persistence.spi.
> PersistenceProvider
> file is nothing more than the name of the implementation class:
> com.acme.PersistenceProvider.
> *Example 2:*
> *A persistence vendor called ACME persistence products ships a module
> called acme.jar that provides persistence provider implementation. The JAR
> contains module definition which contains the name of the implementation
> class.*
> *acme.jar*
> * module-info.class*
> * …*
> *module acme {*
> * provides javax.persistence.spi.PersistenceProvider with
> com.acme.PersistenceProvider;*
> * …*
> *}*
> *The source code of the provider's module definition must contain the name
> of the provider’s implementation class.*
> Persistence provider jars may be installed or made available in the same
> ways as other service providers,
> e.g. as extensions*,* or added to the application classpath according to
> the guidelines in the JAR File
> Specification *or added to the application module path according to the
> guidelines in the Java Platform Module System specification*.
> Do you think this is fine, something should be corrected or is there a
> reason why this second part should not be added to JPA 2.2 MR?
> Thank you,
> --lukas
> [1]:
> [2]: