001/*
002 *    GeoAPI - Java interfaces for OGC/ISO standards
003 *    Copyright © 2013-2023 Open Geospatial Consortium, Inc.
004 *    http://www.geoapi.org
005 *
006 *    Licensed under the Apache License, Version 2.0 (the "License");
007 *    you may not use this file except in compliance with the License.
008 *    You may obtain a copy of the License at
009 *
010 *        http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *    Unless required by applicable law or agreed to in writing, software
013 *    distributed under the License is distributed on an "AS IS" BASIS,
014 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 *    See the License for the specific language governing permissions and
016 *    limitations under the License.
017 */
018package org.opengis.annotation;
019
020import java.lang.annotation.Target;
021import java.lang.annotation.Retention;
022import java.lang.annotation.Documented;
023import static java.lang.annotation.ElementType.*;
024import static java.lang.annotation.RetentionPolicy.*;
025
026
027/**
028 * An annotation specifying the stereotype (abstract, datatype, union, <i>etc.</i>) of an interface.
029 * The UML class diagrams in ISO/OGC specifications declare some members as abstract, meaning that
030 * instances of those interfaces are expected to implement one of their sub-interfaces.
031 * While there is nothing like "abstract interface" and "concrete interface" in the Java language,
032 * we nevertheless communicate ISO/OGC intent using this annotation.
033 *
034 * <p>Implementations are not required to represent "abstract interfaces" by Java abstract classes.
035 * This annotation is provided merely for informative purpose for testing tools, implementations
036 * based on Java reflection, or widgets among other usages.</p>
037 *
038 * <p>If this annotation is not present, then the default value is {@link Stereotype#TYPE}.</p>
039 *
040 * @author  Martin Desruisseaux (Geomatys)
041 * @version 3.1
042 * @since   3.1
043 *
044 * @see <a href="http://en.wikipedia.org/wiki/Classifier_%28UML%29">Classifier on Wikipedia</a>
045 */
046@Documented
047@Retention(RUNTIME)
048@Target(TYPE)
049public @interface Classifier {
050    /**
051     * Returns the type of modeling element (type, datatype, abstract or union).
052     *
053     * @return the type of modeling element as declared in the OGC/ISO UML diagram.
054     */
055    Stereotype value();
056}