ElementType

public final enum ElementType extends Enum<ElementType>

The constants of this enumerated type provide a simple classification of the syntactic locations where annotations may appear in a Java program. These constants are used in java.lang.annotation.Target meta-annotations to specify where it is legal to write annotations of a given type.

The syntactic locations where annotations may appear are split into declaration contexts , where annotations apply to declarations, and type contexts , where annotations apply to types used in declarations and expressions.

The constants ANNOTATION_TYPE , CONSTRUCTOR , FIELD , LOCAL_VARIABLE , METHOD , PACKAGE , PARAMETER , TYPE , and TYPE_PARAMETER correspond to the declaration contexts in JLS 9.6.4.1.

For example, an annotation whose type is meta-annotated with @Target(ElementType.FIELD) may only be written as a modifier for a field declaration.

The constant TYPE_USE corresponds to the 15 type contexts in JLS 4.11, as well as to two declaration contexts: type declarations (including annotation type declarations) and type parameter declarations.

For example, an annotation whose type is meta-annotated with @Target(ElementType.TYPE_USE) may be written on the type of a field (or within the type of the field, if it is a nested, parameterized, or array type), and may also appear as a modifier for, say, a class declaration.

The TYPE_USE constant includes type declarations and type parameter declarations as a convenience for designers of type checkers which give semantics to annotation types. For example, if the annotation type NonNull is meta-annotated with @Target(ElementType.TYPE_USE), then @NonNull class C {...} could be treated by a type checker as indicating that all variables of class C are non-null, while still allowing variables of other classes to be non-null or not non-null based on whether @NonNull appears at the variable's declaration.

Inherited Method Summary

Enum Values

public static final ElementType ANNOTATION_TYPE

Annotation type declaration

public static final ElementType CONSTRUCTOR

Constructor declaration

public static final ElementType FIELD

Field declaration (includes enum constants)

public static final ElementType LOCAL_VARIABLE

Local variable declaration

public static final ElementType METHOD

Method declaration

public static final ElementType PACKAGE

Package declaration

public static final ElementType PARAMETER

Formal parameter declaration

public static final ElementType TYPE

Class, interface (including annotation type), or enum declaration

public static final ElementType TYPE_PARAMETER

Type parameter declaration

public static final ElementType TYPE_USE

Use of a type