FYI, it looks like you are testing out the code from the Spring in Action book. And to let you know that that book is based mostly on Spring 2.0 version. While a lot of that book is still relevant, some of the examples are "older" way of doing things.
For instance in your Advice class, you are now tied to Spring because of the interfaces that you implemented. Where the more POJO clean way is to create a class and add either xml aop tags to declare your joinpoints or with Annotations. This keeps your "Aspect" class a pure Java object.