Remi, Actually I don’t think that statically linking will work. This would produce modules that have overlapping private (non-exported) packages, and such modules also cannot be used in Java 9 on the modulepath.
I tested this in build 9-ea+126-jigsaw-nightly-h5280-20160713 by creating two modules both containing a private package org.example.util. The following exception resulted: java.lang.reflect.LayerInstantiationException: Package org.example.util in both module a and module b. Again this could be “solved” by using custom ClassLoaders or a ClassLoader-based module system like OSGi on Java 9. Neil > On 31 Aug 2016, at 20:28, Remi Forax <fo...@univ-mlv.fr> wrote: > > The other solution is to statically link the right version of slf4j inside > guava and jsoup. > A tool like jarjar can be updated to merge two modular jars (merge two > module-info). > > cheers, > Rémi > > ----- Mail original ----- >> De: "Neil Bartlett" <njbartl...@gmail.com> >> À: cow...@bbs.darktech.org, "Alex Buckley" <alex.buck...@oracle.com> >> Cc: "ZML-OpenJDK-Jigsaw-Developers" <jigsaw-dev@openjdk.java.net> >> Envoyé: Mercredi 31 Août 2016 20:54:44 >> Objet: Re: Multiple versions of a non-exported dependency > >> Gili, >> >> As Alex points out: your use-case can be supported in Java 9 but only with >> the >> addition of custom ClassLoaders, or by using an existing ClassLoader-based >> module system such as OSGi. >> >> The same is also true of Java 8, and Java 7, etc. >> >> Regards, >> Neil >> >> >>> On 31 Aug 2016, at 19:29, Alex Buckley <alex.buck...@oracle.com> wrote: >>> >>> On 8/31/2016 10:56 AM, cowwoc wrote: >>>> I recently became aware of the fact that the Jigsaw specification declared >>>> "version-selection" as a non-goal. While I understand how we ended up here, >>>> I am hoping that you were able to support the following (very common) >>>> use-case: >>>> >>>> * Module "HelloWorld" depends on modules "Guava" and "JSoup". >>>> * Module "Guava" depends on module slf4j version 1 (requires but does not >>>> export it). >>>> * Module "JSoup" depends on module slf4j version 2 (requires but does not >>>> export it). >>>> * slf4j version 2 and is not backwards-compatible with version 1. >>>> >>>> What happens at runtime? Will Jigsaw (out of the box, without 3rd-party >>>> tools like Maven or OSGI) be smart enough to provide different versions of >>>> slf4j to "Guava" and "JSoup"? >>> >>> (You mean Guava/JSoup requires slf4j version 1/2 and does not "re-export" it >>> a.k.a. 'requires public'.) >>> >>> This use case isn't possible on JDK 8 for JARs on the classpath, and it's >>> not >>> supported on JDK 9 for modular JARs on the modulepath: >>> >>> - If you have two versions of a modular JAR slf4j.jar in different >>> directories >>> on the modulepath, then the first one to be found will dominate, and that's >>> what will be resolved for both Guava and JSoup. >>> >>> - If you have two modular JARs slf4j_v1.jar and slf4j_v2.jar on the >>> modulepath, >>> and Guava requires slf4j_v1 and JSoup requires slf4j_v2, then launching >>> 'java >>> -m HelloWorld' will fail. The boot layer will refuse to map the "same" >>> packages >>> from different slf4j_v* modules to the application class loader. >>> >>> The use case _is_ supported on JDK 9 for modular JARs loaded into custom >>> loaders >>> of custom layers. That is, the Java Platform Module System is perfectly >>> capable >>> of supporting the use case -- please see any of my "Jigsaw: Under The Hood" >>> presentations. The use case just isn't supported "out of the box" by the >>> 'java' >>> launcher for JARs on the modulepath. >>> >>> Alex
