Target
@Target([AnnotationTarget.ANNOTATION_CLASS]) class Target
java.lang.annotation.Target |
Indicates the contexts in which an annotation interface is applicable. The declaration contexts and type contexts in which an annotation interface may be applicable are specified in JLS {@jls 9.6.4.1}, and denoted in source code by enum constants of java.lang.annotation.ElementType
.
If an @Target
meta-annotation is not present on an annotation interface T
, then an annotation of type T
may be written as a modifier for any declaration.
If an @Target
meta-annotation is present, the compiler will enforce the usage restrictions indicated by ElementType
enum constants, in line with JLS {@jls 9.7.4}.
For example, this @Target
meta-annotation indicates that the declared interface is itself a meta-annotation interface. It can only be used on annotation interface declarations:
@Target(ElementType.ANNOTATION_TYPE) public @interface MetaAnnotationType { ... }
This @Target
meta-annotation indicates that the declared class or interface is intended solely for use as a member class or interface in complex annotation interface declarations. It cannot be used to annotate anything directly:
@Target({}) public @interface MemberInterface { ... }
It is a compile-time error for a single ElementType
constant to appear more than once in an @Target
annotation. For example, the following @Target
meta-annotation is illegal:
@Target({ElementType.FIELD, ElementType.METHOD, ElementType.FIELD}) public @interface Bogus { ... }
Summary
Public constructors | |
---|---|
Target(vararg value: ElementType) Indicates the contexts in which an annotation interface is applicable. |
Properties | |
---|---|
Array<ElementType> |
Returns an array of the kinds of elements an annotation interface can be applied to. |
Public constructors
Target
Target(vararg value: ElementType)
Indicates the contexts in which an annotation interface is applicable. The declaration contexts and type contexts in which an annotation interface may be applicable are specified in JLS {@jls 9.6.4.1}, and denoted in source code by enum constants of java.lang.annotation.ElementType
.
If an @Target
meta-annotation is not present on an annotation interface T
, then an annotation of type T
may be written as a modifier for any declaration.
If an @Target
meta-annotation is present, the compiler will enforce the usage restrictions indicated by ElementType
enum constants, in line with JLS {@jls 9.7.4}.
For example, this @Target
meta-annotation indicates that the declared interface is itself a meta-annotation interface. It can only be used on annotation interface declarations:
@Target(ElementType.ANNOTATION_TYPE) public @interface MetaAnnotationType { ... }
This @Target
meta-annotation indicates that the declared class or interface is intended solely for use as a member class or interface in complex annotation interface declarations. It cannot be used to annotate anything directly:
@Target({}) public @interface MemberInterface { ... }
It is a compile-time error for a single ElementType
constant to appear more than once in an @Target
annotation. For example, the following @Target
meta-annotation is illegal:
@Target({ElementType.FIELD, ElementType.METHOD, ElementType.FIELD}) public @interface Bogus { ... }
Properties
value
val value: Array<ElementType>
Returns an array of the kinds of elements an annotation interface can be applied to.
Return | |
---|---|
Array<ElementType> |
an array of the kinds of elements an annotation interface can be applied to |