1 /*
   2  * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang.annotation;
  27 
  28 /**
  29  * Indicates the kinds of program element to which an annotation type
  30  * is applicable.  If a Target meta-annotation is not present on an
  31  * annotation type declaration, the declared type may be used on any
  32  * program element.  If such a meta-annotation is present, the compiler
  33  * will enforce the specified usage restriction.
  34  *
  35  * For example, this meta-annotation indicates that the declared type is
  36  * itself a meta-annotation type.  It can only be used on annotation type
  37  * declarations:
  38  * <pre>
  39  *    &#064;Target(ElementType.ANNOTATION_TYPE)
  40  *    public &#064;interface MetaAnnotationType {
  41  *        ...
  42  *    }
  43  * </pre>
  44  * This meta-annotation indicates that the declared type is intended solely
  45  * for use as a member type in complex annotation type declarations.  It
  46  * cannot be used to annotate anything directly:
  47  * <pre>
  48  *    &#064;Target({})
  49  *    public &#064;interface MemberType {
  50  *        ...
  51  *    }
  52  * </pre>
  53  * It is a compile-time error for a single ElementType constant to
  54  * appear more than once in a Target annotation.  For example, the
  55  * following meta-annotation is illegal:
  56  * <pre>
  57  *    &#064;Target({ElementType.FIELD, ElementType.METHOD, ElementType.FIELD})
  58  *    public &#064;interface Bogus {
  59  *        ...
  60  *    }
  61  * </pre>
  62  */
  63 @Documented
  64 @Retention(RetentionPolicy.RUNTIME)
  65 @Target(ElementType.ANNOTATION_TYPE)
  66 public @interface Target {
  67     ElementType[] value();
  68 }