AFAIK, Tomasz is right in saying that this can’t be done using annotations. I think the confusion stems from the fact that Python decorators and Java annotations share the same syntax but are completely different in terms of the behavior they offer!
Annotations are metadata attached to your class/methods/fields. This blog post addresses the point of timing methods using AOP. Though it uses Spring, the basic premise remains the same. If you are good to go with an AOP compiler, it shouldn’t be too difficult to translate the code. Another reference (spring specific) here.
EDIT: If your aim is to have a overall method timing for your application without using full blown profilers, you can use hprof for collecting total execution statistics.