Question

I am somewhat new to Java so perhaps I misunderstand the use cases for annotations in java. My issue is the following:

After annotating a method I receive class names such as $Proxy31 when inspecting the annotations on the method. I am curious why I am receiving class names for my annotations that are similar to this, and what I can do to fix this problem.

Method m = this.remoteServiceClass.getMethod(rpcRequest.getMethod().getName());
RequiredPermission a = m.getAnnotation(RequiredPermission.class);

This returns a null annotation even though I know that the method it is looking up has the RequiredPermission annotation implemented.

for(Annotation a : m.getAnnotations())
{
    System.out.println(a.getClass().getName());
}

This prints out the $Proxy31 class names.

Answer 1

Given Annotation a, you need to call annotationType(), not getClass() to determine the type of the annotation. An Annotation object is just a proxy that represents that instance of the annotation on that class.

Object o = ...;
Class c = o.getClass();
Annotation[] as = c.getAnnotations();
for (Annotation a : as) {
   // prints out the proxy class name
   System.out.println(a.getClass().getName());
   // prints out the name of the actual annotation
   System.out.println(a.annotationType().getName());
}