This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
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.