AnnotationProcessor not being invoked?

[rdehuyss]

Hi all, I'm Ronald, the creator of JobRunr, a distributed job processing framework that integrates with Micronaut.

One feature that we are unable to get working in Micronaut is support for our @Recurring annotation that allows you to create for example a CRON job. The problem is that the @Recurring is inside our core lib and thus cannot depend on the Executable annotation of Micronaut which exposes processOnStartup.

From the docs, I thought this could be solved with a TypedAnnotationMapper:

public class RecurringAnnotationToMicronautMapper implements TypedAnnotationMapper<Recurring> {

    @Override
    public Class<Recurring> annotationType() {
        return Recurring.class;
    }

    @Override
    public List<AnnotationValue<?>> map(AnnotationValue<Recurring> annotation, VisitorContext visitorContext) {
        return List.of(AnnotationValue.builder(Executable.class)
                .member("processOnStartup", true)
                .build());
    }
}

I think I have added everything correctly (see this branch) including the service definition in META-INF/services/io.micronaut.inject.annotation.AnnotationMapper.

If I then consume the locally build jobrunr-micronaut-feature inside a demo project, enable annotation processing using our library and debug, I never hit any of the breakpoints and it looks like the AnnotationMapper is not being executed.

micronaut {
    version '4.8.2'
    runtime("netty")
    testRuntime("junit5")
    processing {
        incremental(false)
        annotations("org.jobrunr.examples.*", "org.jobrunr.micronaut.*")
    }
}

dependencies {
    compileOnly 'io.micronaut:micronaut-inject-java:4.8.2'
    annotationProcessor 'io.micronaut:micronaut-inject-java:4.8.2'
    annotationProcessor 'org.jobrunr:jobrunr-micronaut-feature:1.0.0-SNAPSHOT'
    ...
}

Is this a bug or our we doing something wrong? I think the latter to be honest 😂.

Thanks for your help!

[graemerocher]

the type needs to be on the annotation processor class path so you will need to put the mapper in a separate module

[graemerocher]

no and micronaut-inject-java should never be in compileOnly scope

[rdehuyss]

Hi again @graemerocher ! Thanks for the note about micronaut-inject-java, I removed it. A man tries desperate things when things are not working out hence I tried adding the micronaut-inject-java 😉.

Well, my colleague already tried your approach before me in this project and that also did not work.

There is a separate mapper project for the AnnotationMapper which is then used by the app project where there is an annotation processor configured in the build.gradle using the mapper project. This also did not invoke our custom annotation.

We read the docs over and over again so no idea what we're doing wrong...

[graemerocher]

Weird maybe you can follow the example of other projects. See Micrometer for example https://github.com/micronaut-projects/micronaut-micrometer/tree/5.11.x/micrometer-annotation/src/main/java/io/micronaut/micrometer/annotation/processing

Which adds support for Micrometer's annotations. This separate module is this used here

https://github.com/micronaut-projects/micronaut-micrometer/blob/a5083a9d1f6178a31d0187d5d3beb70920d480e8/micrometer-core/build.gradle.kts#L28

[graemerocher]

Might also be worth writing tests like https://github.com/micronaut-projects/micronaut-micrometer/blob/a5083a9d1f6178a31d0187d5d3beb70920d480e8/micrometer-annotation/src/test/groovy/io/micronaut/micrometer/annotation/processing/AnnotationMappingSpec.groovy

[rdehuyss]

Hi @graemerocher, I've tried everything I can imagine but without success. I created a simple reproducer and opened a bug report.