Use dynamic proxy or AOP for this purpose?

[umark]

Environment: JDK1.6, Spring 2.5.0

I have a Javabean "Service" which provides a number of services:

      Service {
            A()  ; 
            B()  ;
             //...
       }

An access control configuration determines if service X would be
available. Instead of having the bean "Service" consult the
access control, I would like to create a dynamic proxy of "Service" -
say "ServiceP", have it evaluate the access control and invoke
Service:X() or decline:

      class Service {
           @Condition("foo")
            public void A() { /* ... do A ... */ }
            
           @Condition("bar")
             public void B() { /* ... do B ... */ }

            public void freeForAll() { /* ... do freeForAll ... */ }
      }

      class ServiceP /* dynamic proxy of Service */ {
          public void A() {
              // check if condition "foo" is true
              // If yes, call Service.A()
              // If not, print error
              //
           }

            public void B() {
              // check if condition "bar" is true
              // If yes, call Service.B()
              // If not, print error
              //
           }

               public void freeForAll() {
              // No conditions annotated -
              // call Service.B()
              //
           }
      }

Is this an appropriate application of dynamic proxy and
AOP? If so, could you please point me to an illustrative
example?

Tx,

/U

[nikhil78]

You can use a MethodInterceptor or a BeforeAdvice to configure access code for your service. Also, in this case it won't be a generic component as you will code all the checks specific to that service.

Chapter 6 and 7 in the spring reference [shipped with the spring download] is a good starting point to understand AOP proxies.