/* * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ 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(); }