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 * DatasetGroup.java
029 * -----------------
030 * (C) Copyright 2002-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   Tracy Hiltbrand (equals/hashCode comply with EqualsVerifier);
034 *
035 */
036
037package org.jfree.data.general;
038
039import java.io.Serializable;
040import java.util.Objects;
041import org.jfree.chart.util.Args;
042
043/**
044 * A class that is used to group datasets (currently not used for any specific
045 * purpose).
046 */
047public class DatasetGroup implements Cloneable, Serializable {
048
049    /** For serialization. */
050    private static final long serialVersionUID = -3640642179674185688L;
051
052    /** The group id. */
053    private String id;
054
055    /**
056     * Constructs a new group.
057     */
058    public DatasetGroup() {
059        super();
060        this.id = "NOID";
061    }
062
063    /**
064     * Creates a new group with the specified id.
065     *
066     * @param id  the identification for the group.
067     */
068    public DatasetGroup(String id) {
069        Args.nullNotPermitted(id, "id");
070        this.id = id;
071    }
072
073    /**
074     * Returns the identification string for this group.
075     *
076     * @return The identification string.
077     */
078    public String getID() {
079        return this.id;
080    }
081
082    /**
083     * Clones the group.
084     *
085     * @return A clone.
086     *
087     * @throws CloneNotSupportedException not by this class.
088     */
089    @Override
090    public Object clone() throws CloneNotSupportedException {
091        return super.clone();
092    }
093
094    /**
095     * Tests this instance for equality with an arbitrary object.
096     *
097     * @param obj  the object ({@code null} permitted).
098     *
099     * @return A boolean.
100     */
101    @Override
102    public boolean equals(Object obj) {
103        if (obj == this) {
104            return true;
105        }
106        if (!(obj instanceof DatasetGroup)) {
107            return false;
108        }
109        DatasetGroup that = (DatasetGroup) obj;
110        if (!Objects.equals(this.id, that.id)) {
111            return false;
112        }
113        return true;
114    }
115
116    @Override
117    public int hashCode() {
118        int hash = 3;
119        hash = 41 * hash + Objects.hashCode(this.id);
120        return hash;
121    }
122
123}