在列表中查找注释

Question

In my code, I may have annotation defined on methods or fields so what I'm doing is checking both the methods and fields in the class and I store all annotations in a separate list.

Then later I have a method called getAnnotation.

Annotation getAnnotation(Class annotationClass) {
    for (Annotation annotation : annotations) {
        if (annotation.getClass().equals(annotationClass)) {
            return annotation;
        }
    }
    return null;
}

And I call it like this:

Annotation annotation = getAnnotation(MyAnnotation.class);

The problem is that the getAnnotation method does not match up the class names. When I debug I see that the annotations are showing as proxy objects. How can I find the specific annotation that I want in this case?

TIA

I define the map like this:

Map<Class<? extends Annotation>, Annotation> annotations = new HashMap<Class<? extends Annotation>, Annotation>(4);

I populated the Map like this:

Annotation[] annotations = method.getAnnotations();
for (Annotation annotation : annotations) {
  annotations.put(annotation.getClass(), annotation);
}

Answer 1

You'd better populate a Map<Class<? extends Annotation>, Annotation> Map<Class<? extends Annotation>, Annotation> - that way the lookup will be O(1), and you won't care if its a proxy or not.

Answer 2

Yay! I figured it out. The Annotation object has an "annotationType()" method to return the real class name.

So the code for anyone interested would look like this:

Map, Annotation> annotations = new HashMap, Annotation>(4);

Annotation[] annos = method.getAnnotations();
for (Annotation anno : annos) {
    annotations.put(anno.annotationType(), annotation);
}

Then the class matching works fine.