PF4J - JPMS integration

This project is a proof of concept related to how you can integrate PF4J with Java Platform Modules System that comes with Java 9.

Features/Benefits

What I think/feel that are possible:

• a Module from JPMS is equivalent with a Plugin from PF4J
• read plugin metadata from module-info.java (module-info.class), that means to write a custom PluginDescriptorFinder
• read extensions-points and extensions from module-info.java, that means to write a custom ExtensionFinder

When required, PF4J can be forced to use a single class loader for all plugins (the default is to use a class loader for each plugin) via DefaultPluginLoader.createPluginClassLoader(Path pluginPath, PluginDescriptor pluginDescriptor) (returns the same instance).

TODO: add other ideas

PF4J vs JPMS (conceptual)

• In JPMS, the syntax for indicating dependency in a module is asymmetric - you export a package, but require a module.
• In JPMS you export only some packages from a module.

Possible issues

• PF4J uses SemVer but JPMS not. A possible solution is to abstract the work with versions in a VersionManager (interface) and to have the possibility to inject a custom version manager in PluginManager. Resolved by pf4j/pf4j#155.
• find a resource

Resources

• PF4J project
• JPMS very simple demo based on PF4J demo
• JEP 261: Module System