A quick note on intercepting annotations with Spring AOP

Spring AOP is incredibly powerful. One of the most powerful features of the framework is that it lets you intercept methods that are decorated with particular annotations using the following AOP expression :

@annotation(my.package.MyAnnotation)

This can be used in place of :

execution(public * my.package.MyService.serviceMethod(*))

...or in combination with it. But one important point : the annotation being intercepted must be in service method implementations (ie concrete class implementations), not on the service method interface declarations! Otherwise Spring AOP will not be able to read and intercept the annotated methods / classes