001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2020, 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 * CloneUtils.java
029 * ---------------
030 * (C) Copyright 2014-2020, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 */
036package org.jfree.chart.util;
037
038import java.util.ArrayList;
039import java.util.HashMap;
040import java.util.List;
041import java.util.Map;
042
043/**
044 * Utilities for cloning.
045 * 
046 * @since 1.0.18
047 */
048public class CloneUtils {
049    
050    /**
051     * Returns a list containing cloned copies of the items in the source
052     * list.
053     * 
054     * @param source  the source list ({@code null} not permitted).
055     * 
056     * @return A new list. 
057     */
058    public static List<?> cloneList(List<?> source) {
059        Args.nullNotPermitted(source, "source");
060        List result = new ArrayList();
061        for (Object obj: source) {
062            if (obj != null) {
063                try {
064                    result.add(ObjectUtils.clone(obj));
065                } catch (CloneNotSupportedException ex) {
066                    throw new RuntimeException(ex);
067                }
068            } else {
069                result.add(null);
070            }
071        }
072        return result;
073    }
074    
075    /**
076     * Returns a new map that contains the same keys and cloned copied of the
077     * values.
078     * 
079     * @param source  the source map ({@code null} not permitted).
080     * 
081     * @return A new map. 
082     * 
083     * @since 1.0.18
084     */
085    public static Map cloneMapValues(Map source) {
086        Args.nullNotPermitted(source, "source");
087        Map result = new HashMap();
088        for (Object key : source.keySet()) {
089            Object value = source.get(key);
090            if (value != null) {
091                try {
092                    result.put(key, ObjectUtils.clone(value));
093                } catch (CloneNotSupportedException ex) {
094                    throw new RuntimeException(ex);
095                }
096            } else {
097                result.put(key, null);
098            }
099        }
100        return result;
101    }
102   
103}