    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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}