Question

I have a basic Spring MVC controller that looks like this:

@Controller
public void MyController {
     @RequestMapping("/secret")
     public String show() {
         return "secret.jsp";
     }
}

I am going to have several similar URLs that can only be reached by signed-in users. Since this is a cross-cutting concern, I’d like to use AOP, and I’d like to make this work via annotations. In other words, I’d like to throw a @RequiresLogin annotation on every controller method that needs to be secret.

AnnotationMethodHandlerAdapter supports the concept of interceptors, which seems on the surface like the right way to go for this. However, I want to know which method is going to be invoked so that I can check it for my @RequiresLogin annotation. I see that there’s an “Object handler” parameter that’s passed in, but I’m not sure how to turn that into a Class and Method that will be invoked.

Ideas?

Answer 1

As axtavt writes correctly, Spring-AOP works well with controllers if using proxy-target-class. But there is also the possibility of using JDK proxies if you follow some (tedious) conventions:

Working with interface-based @Controller classes

A common pitfall when working with
annotated controller classes happens
when applying functionality that
requires creating a proxy proxy for
the controller object (e.g.
@Transactional methods). Usually you
will introduce an interface for the
controller in order to use JDK dynamic
proxies. To make this work you must
move the @RequestMapping annotations
to the interface as the mapping
mechanism can only “see” the interface
exposed by the proxy. As an
alternative, you may choose to
activate proxy-target-class=”true” in
the configuration for the
functionality applied to the
controller (in our transaction
scenario in <tx:annotation-driven />).
Doing so indicates that CGLIB-based
subclass proxies should be used
instead of interface-based JDK
proxies. For more information on
various proxying mechanisms see
Section 7.6, “Proxying mechanisms”.

Source: 15.3.2 Mapping requests with @RequestMapping