Quarkus CDI with custom annotations

Question

I am currently developing an application respecting as much as possible the principles of hexagonal architecture.

Thus, my "domain" module (groupId: acme ; artifactId: my-domain) does not depend on any technical framework.

All my services are annotated with a custom annotation (itself part of my domain):

package acme.domain;

@Target({ElementType.TYPE})
@Retention(value = RetentionPolicy.RUNTIME)
public @interface DomainService {
}

However, in my "Quarkus application" module (groupId: acme ; artifactId: app-quarkus), I need to inject services defined in my "domain" module (acme:domain).

With SpringBoot, it is quite easy to inject those domain services (based on a custom annotation) with the following annotation:

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.FilterType;

@SpringBootApplication
@ComponentScan(
    basePackageClasses = {CourtageSpringbootApplication.class, DomainService.class},
    includeFilters = {@ComponentScan.Filter(type = FilterType.ANNOTATION, value = {DomainService.class})}
)
public class MySpringbootApplication {
}

Is there an equivalent to @ComponentScan with Quarkus?

NB : I have added following lines in app-quarkus/src/main/resources/application.properties but it does not work:

quarkus.index-dependency.courtage.group-id=acme
quarkus.index-dependency.courtage.artifact-id=my-domain

Thrown exception: javax.enterprise.inject.UnsatisfiedResolutionException

Answer 1

First of all, I would personally consider strictly avoiding CDI annotations in your domain module a little bit overzealous. But if you really want that, I can see 2 options:

1. You could limit yourself to only placing CDI annotations on your own annotations, and use @Stereotype. For example, if your @DomainService should be equivalent to @ApplicationScoped, it could be declared like this:

   @Stereotype
   @ApplicationScoped
   @Target({ElementType.TYPE})
   @Retention(value = RetentionPolicy.RUNTIME)
   public @interface DomainService {
   }
   

2. If you absolutely insist that no CDI annotation should ever be present in the domain module, you could create a Quarkus extension that would register @DomainService as a custom bean defining annotation. The Quarkus CDI Integration guide has more details about that: https://quarkus.io/guides/cdi-integration You would either use AutoAddScopeBuildItem or BeanDefiningAnnotationBuildItem.