Enum Class ElementType
- All Implemented Interfaces:
Serializable
,Comparable<ElementType>
,Constable
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
, MODULE
, PARAMETER
, TYPE
, and TYPE_PARAMETER
correspond to the declaration contexts in JLS 9.6.4.1.
For example, an annotation whose interface 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 type contexts in JLS
4.11, as well as to two declaration contexts: class and interface
declarations (including annotation declarations) and type parameter
declarations.
For example, an annotation whose interface is meta-annotated with
@Target(ElementType.TYPE_USE)
may be written on the class or
interface of a field (or within the class or interface of the field, if it
is a nested or parameterized class or interface, or array class), and may
also appear as a modifier for, say, a class declaration.
The TYPE_USE
constant includes class and interface declarations
and type parameter declarations as a convenience for designers of
type checkers which give semantics to annotation interfaces. For example,
if the annotation interface 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.
- See Java Language Specification:
-
9.6.4.1 @Target
4.1 The Kinds of Types and Values - Since:
- 1.5
-
Nested Class Summary
Nested classes/interfaces declared in class java.lang.Enum
Enum.EnumDesc<E extends Enum<E>>
-
Enum Constant Summary
Enum ConstantDescriptionAnnotation interface declaration (Formerly known as an annotation type.)Constructor declarationField declaration (includes enum constants)Local variable declarationMethod declarationModule declaration.Package declarationFormal parameter declarationRecord componentClass, interface (including annotation interface), enum, or record declarationType parameter declarationUse of a type -
Method Summary
Modifier and TypeMethodDescriptionstatic ElementType
Returns the enum constant of this class with the specified name.static ElementType[]
values()
Returns an array containing the constants of this enum class, in the order they are declared.
-
Enum Constant Details
-
TYPE
Class, interface (including annotation interface), enum, or record declaration -
FIELD
Field declaration (includes enum constants) -
METHOD
Method declaration -
PARAMETER
Formal parameter declaration -
CONSTRUCTOR
Constructor declaration -
LOCAL_VARIABLE
Local variable declaration -
ANNOTATION_TYPE
Annotation interface declaration (Formerly known as an annotation type.) -
PACKAGE
Package declaration -
TYPE_PARAMETER
-
TYPE_USE
-
MODULE
-
RECORD_COMPONENT
Record component- See Java Language Specification:
-
8.10.3 Record Members
9.7.4 Where Annotations May Appear - Since:
- 16
-
-
Method Details
-
values
Returns an array containing the constants of this enum class, in the order they are declared.- Returns:
- an array containing the constants of this enum class, in the order they are declared
-
valueOf
Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)- Parameters:
name
- the name of the enum constant to be returned.- Returns:
- the enum constant with the specified name
- Throws:
IllegalArgumentException
- if this enum class has no constant with the specified nameNullPointerException
- if the argument is null
-