Validate Java EE Annotations With Annotation Processors

Overview

The annotation facility is widely used in Java EE 5 and other frameworks, but it needs a validation facility to check the semantic constraints. Apt is a great tool for creating annotation processors to validate EE annotations at build time. The apt-based, build-time annotation validation is complementary to run-time reflection-based validation. It is especially useful when the annotations are not available at run time. The upcoming JSR-269 defines a standardized annotation process API to supersede the apt API. The new annotation processing API is easy to use and preferred, even though apt remains supported in the next release of Java.