# Print output for @column tags ?>
public
final
enum
ElementType
extends Enum<ElementType>
java.lang.Object | ||
↳ | java.lang.Enum<java.lang.annotation.ElementType> | |
↳ | java.lang.annotation.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 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.
Enum values | |
---|---|
ElementType |
ANNOTATION_TYPE
Annotation type declaration |
ElementType |
CONSTRUCTOR
Constructor declaration |
ElementType |
FIELD
Field declaration (includes enum constants) |
ElementType |
LOCAL_VARIABLE
Local variable declaration |
ElementType |
METHOD
Method declaration |
ElementType |
PACKAGE
Package declaration |
ElementType |
PARAMETER
Formal parameter declaration |
ElementType |
TYPE
Class, interface (including annotation type), or enum declaration |
ElementType |
TYPE_PARAMETER
Type parameter declaration |
ElementType |
TYPE_USE
Use of a type |
Public methods | |
---|---|
static
ElementType
|
valueOf(String name)
|
static
final
ElementType[]
|
values()
|
Inherited methods | |
---|---|
public static final ElementType TYPE
Class, interface (including annotation type), or enum declaration