001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ---------------
028 * KeyedValue.java
029 * ---------------
030 * (C) Copyright 2002-2008, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes:
036 * --------
037 * 31-Oct-2002 : Version 1 (DG);
038 * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.base (DG);
039 *
040 */
041
042package org.jfree.data;
043
044/**
045 * A (key, value) pair.
046 *
047 * @see DefaultKeyedValue
048 */
049public interface KeyedValue extends Value {
050
051    /**
052     * Returns the key associated with the value.  The key returned by this
053     * method should be immutable.
054     *
055     * @return The key (never <code>null</code>).
056     */
057    public Comparable getKey();
058
059}