001    /*
002     *    GeoAPI - Java interfaces for OGC/ISO standards
003     *    http://www.geoapi.org
004     *
005     *    Copyright (C) 2006-2012 Open Geospatial Consortium, Inc.
006     *    All Rights Reserved. http://www.opengeospatial.org/ogc/legal
007     *
008     *    Permission to use, copy, and modify this software and its documentation, with
009     *    or without modification, for any purpose and without fee or royalty is hereby
010     *    granted, provided that you include the following on ALL copies of the software
011     *    and documentation or portions thereof, including modifications, that you make:
012     *
013     *    1. The full text of this NOTICE in a location viewable to users of the
014     *       redistributed or derivative work.
015     *    2. Notice of any changes or modifications to the OGC files, including the
016     *       date changes were made.
017     *
018     *    THIS SOFTWARE AND DOCUMENTATION IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE
019     *    NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
020     *    TO, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT
021     *    THE USE OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY
022     *    PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
023     *
024     *    COPYRIGHT HOLDERS WILL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL OR
025     *    CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE OR DOCUMENTATION.
026     *
027     *    The name and trademarks of copyright holders may NOT be used in advertising or
028     *    publicity pertaining to the software without specific, written prior permission.
029     *    Title to copyright in this software and any associated documentation will at all
030     *    times remain with copyright holders.
031     */
032    package org.opengis.filter.identity;
033    
034    /**
035     * An object identifier.
036     * <p>
037     * This class is an abstract base for identifiers. Some known identifiers are:
038     * <ul>
039     *   <li>FeatureId</li>
040     *   <li>GMLObjectId</li>
041     *   <li>RecordId</li>
042     * </ul>
043     * </p>
044     *
045     * @param <T> The type of the identifier itself.
046     * @param <O> The type of objects to be identified.
047     *
048     * @version <A HREF="http://www.opengis.org/docs/02-059.pdf">Implementation specification 1.0</A>
049     * @author Jody Garnett (Refractions Research)
050     * @author Justin Deoliveira (The Open Planning Project)
051     */
052    public interface Identifier {
053        /**
054         * Returns the identifier itself.
055         */
056        Object getID();
057    
058        /**
059         * Determines if the id of an object matches the value of the identifier.
060         *
061         * @param object The object to perform the test against.
062         * @return {@code true} if a match, otherwise {@code false}.
063         */
064        boolean matches(Object object);
065    
066        /**
067         * Identifier is a data object, equals is based just on getID()
068         * @param obj
069         * @return true if obj is an Identifier with the same getID()
070         */
071        @Override
072        public boolean equals(Object obj);
073        
074        /**
075         * Identifier is a data object, hashCode is based just on getID()
076         * @return hashCode based on getID()
077         */
078        @Override
079        public int hashCode();
080        
081        /**
082         * Returns a string representation of the identifier.
083         * @return getID().toString()
084         */
085        @Override 
086        String toString();
087    }