001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, 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 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * -----------------
028 * DatasetGroup.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 * 07-Oct-2002 : Version 1 (DG);
038 * 26-Mar-2003 : Implemented Serializable (DG);
039 * 20-Aug-2003 : Implemented Cloneable (DG);
040 *
041 */
042
043package org.jfree.data.general;
044
045import java.io.Serializable;
046
047/**
048 * A class that is used to group datasets (currently not used for any specific
049 * purpose).
050 */
051public class DatasetGroup implements Cloneable, Serializable {
052
053    /** For serialization. */
054    private static final long serialVersionUID = -3640642179674185688L;
055
056    /** The group id. */
057    private String id;
058
059    /**
060     * Constructs a new group.
061     */
062    public DatasetGroup() {
063        super();
064        this.id = "NOID";
065    }
066
067    /**
068     * Creates a new group with the specified id.
069     *
070     * @param id  the identification for the group.
071     */
072    public DatasetGroup(String id) {
073        if (id == null) {
074            throw new IllegalArgumentException("Null 'id' argument.");
075        }
076        this.id = id;
077    }
078
079    /**
080     * Returns the identification string for this group.
081     *
082     * @return The identification string.
083     */
084    public String getID() {
085        return this.id;
086    }
087
088    /**
089     * Clones the group.
090     *
091     * @return A clone.
092     *
093     * @throws CloneNotSupportedException not by this class.
094     */
095    public Object clone() throws CloneNotSupportedException {
096        return super.clone();
097    }
098
099    /**
100     * Tests this instance for equality with an arbitrary object.
101     *
102     * @param obj  the object (<code>null</code> permitted).
103     *
104     * @return A boolean.
105     */
106    public boolean equals(Object obj) {
107        if (obj == this) {
108            return true;
109        }
110        if (!(obj instanceof DatasetGroup)) {
111            return false;
112        }
113        DatasetGroup that = (DatasetGroup) obj;
114        if (!this.id.equals(that.id)) {
115            return false;
116        }
117        return true;
118    }
119
120}