How to declare a generic Class extending an annotation

Question

I'm working on an annotation processor and I would pass to my class a parameter representing the annotation to manage, something like: Class<? extends @interface> annotationClass

Unfortunately this does not compile. The only way I can compile is using a raw type Class but in this way when I try something like

roundEnvironment.getElementsAnnotatedWith(annotationClass)

the returned type is an Object instead of a javax.lang.model.element.Element

public Map<ClassName, List<ElementInfo>> initClassesToGenerate(Class annotationClass, ElementKind elementKind, RoundEnvironment roundEnvironment) {

        Map<ClassName, List<ElementInfo>> result = new HashMap<>();

        // init map

        for (Element annotatedElement : roundEnvironment.getElementsAnnotatedWith(annotationClass)) {

            TypeElement typeElement = (TypeElement) annotatedElement;
            ClassName className = ClassName.get(typeElement);
            if (!result.containsKey(className)) {
                result.put(className, new ArrayList<>());
            }
        }

        return result;
}

No problem. Answer form below is more useful (thanks @cameron1024). — BeUndead, Jan 28 '20 at 16:56

score 2 · Accepted Answer · answered Jan 28 '20 at 16:56

2

You can use <T extends Annotation>. You can then use Class<T> to reference classes of annotations.

answered Jan 28 '20 at 16:56

cameron1024

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How to declare a generic Class extending an annotation

1 Answers1