orblazer / velocity-jpms

Proof of concept for JPMS in Velocity

Velocity JPMS (Java Platform Module System or Jigsaw)

This repo is a proof of concept for implementing JPMS on Velocity plugins.

Current State

When app is module : SUCCESS (with warning)

In this mode, currently we need to use distribution archive (at app/build/distributions) with embedded script or use

java -p lib -m org.example.jpms

Warning generated

SLF4J warn with the following message because in 2.0.x is required to use ServiceLoader

SLF4J: No SLF4J providers were found.
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#noProviders for further details.
SLF4J: Class path contains SLF4J bindings targeting slf4j-api versions prior to 1.8.
SLF4J: Ignoring binding found at [jar:file:///home/orblazer/dev/java/test/lib/log4j-slf4j-impl-2.18.0.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#ignoredBindings for an explanation.

When app is fatjar : BROKEN

This is currently broken due to the fatjar for app, so that generate following error because the api is not considerate as a module.

[ERROR]: Couldn't load plugins
java.lang.module.FindException: Module org.example.jpms.api not found, required by org.example.plugin
        at java.lang.module.Resolver.findFail(Resolver.java:893) ~[?:?]
        at java.lang.module.Resolver.resolve(Resolver.java:192) ~[?:?]
        at java.lang.module.Resolver.resolve(Resolver.java:141) ~[?:?]
        at java.lang.module.Configuration.resolveAndBind(Configuration.java:492) ~[?:?]
        at java.lang.module.Configuration.resolveAndBind(Configuration.java:298) ~[?:?]
        at org.example.jpms.app.plugin.PluginManager.loadPlugins(PluginManager.java:59) ~[app-1.0-SNAPSHOT-all.jar:1.0-SNAPSHOT]
        at org.example.jpms.app.App.loadPlugins(App.java:72) ~[app-1.0-SNAPSHOT-all.jar:1.0-SNAPSHOT]
        at org.example.jpms.app.App.start(App.java:43) ~[app-1.0-SNAPSHOT-all.jar:1.0-SNAPSHOT]
        at org.example.jpms.app.Bootstrap.main(Bootstrap.java:20) ~[app-1.0-SNAPSHOT-all.jar:1.0-SNAPSHOT]

For fix that issue we need to use named module for app but that add some difficulties for run the server. The following list explain what it's possible for achieve that.

1. [ideal] Have a launcher jar that download/extract all needed libraries/modules (like PaperClip)

   PS: without that we need copy all required libraries into a folder and run the app with something like that :

   java -p libs:. -m org.example.jpms

2. Keep the fatjar but download/extract api into a folder and load it into plugin ModuleLayer.