Extensions.idx files get not generated in Elipse although annotation processing is activated

[egloffmark]

I tried to run your demo application with the development mode (-Dpf4j.mode=development) in Eclipse. I realized that the extension files get not generated in the "target/classes/META-INF" folder although I have activated on the plugin projects the Java compiler option "Enable Annotation Processing".

If I run the Maven build to produce the jar files then the extension files are packed inside the jar files. So I assume it is a problem of the Eclipse processing? I am using Eclipse v2019-03 and Java 1.8 and version 0.5.0 of your project

Please see the log statements when I start your demo "boot" application
log.txt

[egloffmark]

It is definitely an eclipse issue - if I just run "maven compile" then the "extensions.idx" files get generated.

I could solve the issue by either configuring Eclipse to use for the Annotations your "pf4j-2.6.0.jar" by adding it explicitly to the "FactoryPath" in the Annotations Settings. This of course is not a preferred option so I need to have always the jar file located somewhere and maintained.

The better way is to use the additional eclipse plugin "m2e-apt" (https://marketplace.eclipse.org/content/m2e-apt). This generates a new configuration menu option at the project settings. There you can activate / synchronize the annotation processing with the maven plugin.

However not sure why such an explicit configuration / workaround is necessary. May be Eclipse has changed or your PF4J project need to be updated so Eclipse would automatically detect the annotation processors when the processing has been activated? would be good if you can clarify this issue.

[decebals]

They are some issues that make reference to Eclipse:

• Can't open project as maven project in eclipse pf4j#258
• Why is the result of PluginManager.getExtensions empty? pf4j#249

For no extensions issue:

• Why is the result of PluginManager.getExtensions empty? pf4j#249 (comment)
• not find META-INF/extensions.idx pf4j#21 (comment)

I don't use Eclipse in my projects so I know too much about it, but I am sure that a lot of PF4J users use Eclipse. If I can improve something please create a PR or add a comment with what I can do.

[cwiechmann]

I'm using Eclipse as well and can confirm, that I'm having exactly the same problem. Just added the pf4j....jar to the "Factory path" as shown above and with that it is working.
@decebals, I'm unfortunately not used to the Java Annotations API and missed some background information about what it does or should do.
Therefore I'm thinking it might be worth to add a few more words about it at this place:

PF4J uses Java Annotation Processing to process at compile time all classes annotated with @extension and to produce the extensions index file.

And maybe add a link for further reading.