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 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 { ... }
- See Java Language Specification:
-
9.6.4.1 @Target
9.7.4 Where Annotations May Appear
9.7.5 Multiple Annotations of the Same Interface - Since:
- 1.5
-
Required Element Summary
Modifier and TypeRequired ElementDescriptionReturns an array of the kinds of elements an annotation interface can be applied to.
-
Element Details
-
value
ElementType[] valueReturns an array of the kinds of elements an annotation interface can be applied to.- Returns:
- an array of the kinds of elements an annotation interface can be applied to
-