Inconsistency with 'meta' annotations

[sifraser]

I was hoping I would be able to use this library to work with 'meta' (aggregated) annotations in a similar to Spring (https://docs.spring.io/spring/docs/4.0.0.RELEASE/spring-framework-reference/htmlsingle/#beans-meta-annotations).

At first I was hopeful as getTypesAnnotatedWith() appears to successfully match classes with an indirect/meta annotation e.g.

@Target(ElementType.TYPE)
@Retention(RUNTIME)
@interface Meta {
    String value();
}

@Meta("a")
@Retention(RUNTIME)
@interface A {}

@Meta("b")
@Retention(RUNTIME)
@interface B {}

@A class A1 {}
@B class B1 {}
@A class A2 {}

public class Annotations {
    public static void main(String[] args) {
        for (Class<?> type: new Reflections().getTypesAnnotatedWith(Meta.class)) {
            System.out.println(type.getSimpleName());
        }
    }
}

Prints:

B1
A
A1
A2
B

Which is great as A1, A2 and B1 are all matching without an explicitly declared annotation.

My problem is that although I now know that A1, A2 and B1 have an indirect Meta annotation, I cannot actually get hold of a reference to it. I have tried numerous mechanisms including with ReflectionUtils e.g.

for (Annotation annotation : ReflectionUtils.getAnnotations(A1.class)) {
    System.out.println(annotation.annotationType().getSimpleName());
}

But everything just gives the explicitly declared annotations, i.e.:

A

(By everything, I mean that I have tried everything obvious - there is probably some way to process the store directly that I have not considered.)

So effectively I have two issues:

• There is an inconsistency on which annotations a type 'has'
• I cannot use meta annotations without additional boilerplate to explicitly check annotations of annotations

A correct solution would probably require some explicit handling of this form of annotation aggregation.

[dota17]

This is a good job! And I have a question, do we need to add a switch to enable people to distinguish between explicit and implicit annotations in case that some people need the old features and the others need the this new feature?