001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * KeyedValuesItemKey.java
029 * -----------------------
030 * (C) Copyright 2014-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   Tracy Hiltbrand;
034 *
035 */
036
037package org.jfree.data;
038
039import java.io.Serializable;
040import org.jfree.chart.util.Args;
041
042/**
043 * A key that references one item in a {@link KeyedValues} data structure.
044 */
045public class KeyedValuesItemKey implements ItemKey, Serializable {
046    
047    /** The key for the item. */
048    Comparable<?> key;
049    
050    /**
051     * Creates a new instance.
052     * 
053     * @param key  the key ({@code null} not permitted).
054     */
055    public KeyedValuesItemKey(Comparable<?> key) {
056        Args.nullNotPermitted(key, "key");
057        this.key = key;
058    }
059    
060    /**
061     * Returns the key.
062     * 
063     * @return The key (never {@code null}). 
064     */
065    public Comparable<?> getKey() {
066        return this.key;
067    }
068    
069    /**
070     * Tests this instance for equality with an arbitrary object.
071     * 
072     * @param obj  the object ({@code null} not permitted).
073     * 
074     * @return A boolean.
075     */
076    @Override
077    public boolean equals(Object obj) {
078        if (obj == this) {
079            return true;
080        }
081        if (!(obj instanceof KeyedValuesItemKey)) {
082            return false;
083        }
084        KeyedValuesItemKey that = (KeyedValuesItemKey) obj;
085        if (!this.key.equals(that.key)) {
086            return false;
087        }
088        return true;
089    }
090    
091    @Override
092    public String toJSONString() {
093        StringBuilder sb = new StringBuilder();
094        sb.append("{\"key\": \"").append(this.key.toString()).append("\"}");
095        return sb.toString();
096    }
097
098    @Override
099    public String toString() {
100        StringBuilder sb = new StringBuilder();
101        sb.append("KeyedValuesItemKey[");
102        sb.append(this.key.toString());
103        sb.append("]");
104        return sb.toString();
105    }
106}