Type Annotations Specification (JSR 308) Michael D. Ernst
[email protected] May 2, 2013 The JSR 308 webpage is http://types.cs.washington.edu/jsr308/. It contains the latest version of this document, along with other information such as a FAQ, the reference implementation, and sample annotation processors. Contents 1 Introduction 2 2 Java language syntax extensions 2 2.1 Source locations for annotations on types . 2 2.1.1 Implicit type uses are not annotatable . 5 2.1.2 Not all type names are annotatable . 5 2.2 Java language grammar changes . 6 2.2.1 Syntax of array annotations . 8 2.2.2 Syntax of annotations on qualified types . 9 2.3 Target meta-annotations for type annotations . 9 3 Class file format extensions 11 3.1 The type annotation structure . 12 3.2 The target type field: the type of annotated element . 13 3.3 The target info field: identifying a program element . 13 3.3.1 Type parameters . 13 3.3.2 Class supertypes: extends and implements clauses . 14 3.3.3 Type parameter bounds . 14 3.3.4 Method return type, receiver, and fields . 15 3.3.5 Method formal parameters . 15 3.3.6 throws clauses . 15 3.3.7 Local variables and resource variables . 15 3.3.8 Exception parameters (catch clauses) . 16 3.3.9 Type tests, object creation, and method/constructor references . 16 3.3.10 Casts and type arguments to constructor/method invocation/references . 16 3.4 The type path structure: Identifying part of a compound type . 17 A Examples of classfile structure 18 A.1 Examples of type parameter bounds .