Inheritance in annotations

Question

I'm trying to make a method that returns fields that are annotated with a specific annotation.

I have one annotation (TestAnn) that I want to be a superclass for the other two (AutoSave and AutoLoad).

TestAnn:

public @interface TestAnn {

    boolean value() default true;

}

AutoSave and AutoLoad (their code are the same):

@TestAnn
public @interface AutoSave {


    boolean value() default true;

}

Method to get fields:

private List<Field> getFields(Mode mode){
    Class<? extends TestAnn> an;
    if (mode == Mode.SAVE){
        an = AutoSave.class;
    }
    else if (mode == Mode.LOAD){
        an = AutoLoad.class;
    }
    else{
        throw new RuntimeException();
    }

    return null;
}

So I tried to annotate AutoSave and AutoLoad with @TestAnn in hope that it is how inheritance works for annotations. But when I try to assign a specific annotation class to wildcard <? extends TestAnn>, the compiler says I can't do that.

So is there some sort of inheritance for annotations? If you provide code for my specific case it would be very helpful. Thanks!

@Sweeper Get all the fields with the appropriate (AutoLoad or AutoSave) annotation on them. — Rubix327, Oct 19 '22 at 20:56
Annotations are not themselves polymorphic. They cannot extend other annotations, nor any other interface for that matter. The dupe targets are pretty old, but the situation has not changed. — John Bollinger, Oct 19 '22 at 20:58
@JohnBollinger So how do I get all the class fields with dynamically defined annotation? — Rubix327, Oct 19 '22 at 21:01
@JohnBollinger Nothing. I'm just trying to solve my problem... — Rubix327, Oct 19 '22 at 21:14
Though I should clarify: all annotations do extend `java.lang.annotation.Annotation`, so they have (very) limited polymorphism in that sense. You might find that useful, but I don't see its direct use as *necessary* here. — John Bollinger, Oct 19 '22 at 21:14

Inheritance in annotations

0 Answers0