Types and hierarchies of packages comprising a Java language model, a model of the declarations and types of the Java programming language. The members of this package and its subpackages are for use in language modeling and language processing tasks and APIs including, but not limited to, the annotation processing framework.

This language model follows a mirror-based design; see

Gilad Bracha and David Ungar. Mirrors: Design Principles for Meta-level Facilities of Object-Oriented Programming Languages. In Proc. of the ACM Conf. on Object-Oriented Programming, Systems, Languages and Applications, October 2004.

In particular, the model makes a distinction between declared language constructs, like the element representing java.util.Set, and the family of types that may be associated with an element, like the raw type java.util.Set, java.util.Set<String>, and java.util.Set<T>.

Unless otherwise specified, methods in this package will throw a NullPointerException if given a null argument.