001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, 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 2002-2005, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: DatasetGroup.java,v 1.4.2.1 2005/10/25 21:32:29 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 07-Oct-2002 : Version 1 (DG);
040     * 26-Mar-2003 : Implemented Serializable (DG);
041     * 20-Aug-2003 : Implemented Cloneable (DG);
042     *
043     */
044    
045    package org.jfree.data.general;
046    
047    import java.io.Serializable;
048    
049    /**
050     * A class that is used to group datasets (currently not used for any specific
051     * purpose).
052     */
053    public class DatasetGroup implements Cloneable, Serializable {
054        
055        /** For serialization. */
056        private static final long serialVersionUID = -3640642179674185688L;
057        
058        /** The group id. */
059        private String id;
060        
061        /**
062         * Constructs a new group.
063         */
064        public DatasetGroup() {
065            super();
066            this.id = "NOID";
067        }
068    
069        /**
070         * Creates a new group with the specified id.
071         * 
072         * @param id  the identification for the group.
073         */
074        public DatasetGroup(String id) {
075            if (id == null) {
076                throw new IllegalArgumentException("Null 'id' argument.");   
077            }
078            this.id = id;   
079        }
080        
081        /**
082         * Returns the identification string for this group.
083         * 
084         * @return The identification string.
085         */
086        public String getID() {
087            return this.id;   
088        }
089        
090        /**
091         * Clones the group.
092         * 
093         * @return A clone.
094         * 
095         * @throws CloneNotSupportedException not by this class.
096         */
097        public Object clone() throws CloneNotSupportedException {
098            return super.clone();    
099        }
100        
101        /**
102         * Tests this instance for equality with an arbitrary object.
103         * 
104         * @param obj  the object (<code>null</code> permitted).
105         * 
106         * @return A boolean.
107         */
108        public boolean equals(Object obj) {
109            if (obj == this) {
110                return true;   
111            }
112            if (!(obj instanceof DatasetGroup)) {
113                return false;   
114            }
115            DatasetGroup that = (DatasetGroup) obj;
116            if (!this.id.equals(that.id)) {
117                return false;   
118            }
119            return true;
120        }
121        
122    }