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package java.lang.annotation;

/**
 * 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 {@link ElementType java.lang.annotation.ElementType}.
 *
 * 

If an {@code @Target} meta-annotation is not present on an annotation * interface {@code T}, then an annotation of type {@code T} may be written as * a modifier for any declaration. * *

If an {@code @Target} meta-annotation is present, the compiler will enforce * the usage restrictions indicated by {@code ElementType} * enum constants, in line with JLS {@jls 9.7.4}. * *

For example, this {@code @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 {@code @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 {@code ElementType} constant to * appear more than once in an {@code @Target} annotation. For example, the * following {@code @Target} meta-annotation is illegal: *

 *    @Target({ElementType.FIELD, ElementType.METHOD, ElementType.FIELD})
 *    public @interface Bogus {
 *        ...
 *    }
 * 
* * @since 1.5 * @jls 9.6.4.1 @Target * @jls 9.7.4 Where Annotations May Appear * @jls 9.7.5 Multiple Annotations of the Same Interface */ @Documented @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.ANNOTATION_TYPE) public @interface Target { /** * Returns an array of the kinds of elements an annotation interface * can be applied to. * @return an array of the kinds of elements an annotation interface * can be applied to */ ElementType[] value(); }




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