Annotation is not inherited from interface method

Question

I have an interface with an annotated method. The annotation is marked with @Inherited, so I expect an implementor to inherit it. However, it is not the case:

Answer 1

From the javadocs of java.lang.annotation.Inherited:

Note that this meta-annotation type has no effect if the annotated type is used to annotate anything other than a class. Note also that this meta-annotation only causes annotations to be inherited from superclasses; annotations on implemented interfaces have no effect.

Answer 2

From the @Inherited javadoc:

Note that this meta-annotation type has no effect if the annotated type is used to annotate anything other than a class. Note also that this meta-annotation only causes annotations to be inherited from superclasses; annotations on implemented interfaces have no effect.`

In summary, it doesn't apply to methods.

Answer 3

Alternatively, you can use reflection to derive the same information. The method printMethodAnnotations can be rewritten as:

private static void printMethodAnnotations(Method m) {
    Class<?> methodDeclaredKlass = m.getDeclaringClass();
    List<Class<?>> interfases = org.apache.commons.lang3.ClassUtils.getAllInterfaces(methodDeclaredKlass);
    List<Annotation> annotations = new ArrayList<>();
    annotations.addAll(Arrays.asList(m.getAnnotations()));
    for (Class<?> interfase : interfases) {
        for (Method interfaseMethod : interfase.getMethods()) {
            if (areMethodsEqual(interfaseMethod, m)) {
                annotations.addAll(Arrays.asList(interfaseMethod.getAnnotations()));
                continue;
            }
        }
    }
    System.out.println(m + "*: " + annotations);
}

private static boolean areMethodsEqual(Method m1, Method m2) {
    // return type, Modifiers are not required to check, if they are not appropriate match then it will be a compile
    // time error. This needs enhancements for Generic types parameter ?
    return m1.getName().equals(m2.getName()) && Arrays.equals(m1.getParameterTypes(), m2.getParameterTypes());
}