XmlBeans preparation for modules and multi-release jar

[Andreas Beeker <ki...@apache.org>]

Hi *,

as noted before, I've prepared a patch for xmlbeans resources within a poi specific namespace opposed to the usual schemaorg_apache_xmlbeans directory. This was due some modularization effort for Java 11 [1], but in the end might not be necessary as the "opens" directive had to be used.

i would like to put more effort in getting POI ready for Jigsaw/Java 9 module paths ... and have to admit, that this is still experimental for me and maybe you have already more experience in this,

With the goal of having no "opens" anymore, I would try the following to progress forward:
- based on [2], I would try to get rid of the schemaorg_apache_xmlbeans directory within the xmlbeans dist
- try multi-release jars for xmlbeans [3] with Java 6 / 9
- apply [2] to POI
- try multi-release on POI with Java 8 / 9 / 10 / 11 - look at the build file for the specifics on each version, maybe we can ignore Java 10 compatibility

My hope is that it's possible to provide a module-info.java per java version.

The changes will lead to a new ooxml-schema version.

What do you think?

- is it worth the effort?
- should we wait for further changes / poi 5.0?
- any caveats?

Best wishes,
Andi


[1] http://apache-poi.1045710.n5.nabble.com/Problems-using-poi-with-JDK-11-in-a-modularized-application-tp5732725.html

[2] http://people.apache.org/~kiwiwings/xmlbeans/

[3] http://openjdk.java.net/jeps/238