When are Java annotations executed?

Question

I am just looking to write some annotation which can execute at runtime, before or immediately after a service method is invoked.

I don\'t know if they are executed at r

Answer 1

Annotations don't execute; they're notes or markers that are read by various tools. Some are read by your compiler, like @Override; others are embedded in the class files and read by tools like Hibernate at runtime. But they don't do anything themselves.

You might be thinking of assertions instead, which can be used to validate pre and post conditions.