/* * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ package java.lang.annotation; /** * Indicates the contexts in which an annotation type is applicable. The * declaration contexts and type contexts in which an annotation type may be * applicable are specified in 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 type * {@code T} , then an annotation of type {@code T} may be written as a * modifier for any declaration except a type parameter 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 9.7.4. * *
For example, this {@code @Target} meta-annotation indicates that the * declared type is itself a meta-annotation type. It can only be used on * annotation type declarations: *
* @Target(ElementType.ANNOTATION_TYPE) * public @interface MetaAnnotationType { * ... * } ** *
This {@code @Target} meta-annotation indicates that the declared type is * intended solely for use as a member type in complex annotation type * declarations. It cannot be used to annotate anything directly: *
* @Target({}) * public @interface MemberType { * ... * } ** *
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 */ @Documented @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.ANNOTATION_TYPE) public @interface Target { /** * Returns an array of the kinds of elements an annotation type * can be applied to. * @return an array of the kinds of elements an annotation type * can be applied to */ ElementType[] value(); }