001    /**
002     * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.kernel.util;
016    
017    import java.util.Enumeration;
018    import java.util.Properties;
019    import java.util.Vector;
020    
021    /**
022     * @author Brian Wing Shun Chan
023     */
024    public class OrderedProperties extends Properties {
025    
026            public OrderedProperties() {
027                    _names = new Vector<>();
028            }
029    
030            @Override
031            public Enumeration<String> propertyNames() {
032                    return _names.elements();
033            }
034    
035            @Override
036            public Object put(Object key, Object value) {
037                    if (_names.contains(key)) {
038                            _names.remove(key);
039                    }
040    
041                    _names.add((String)key);
042    
043                    return super.put(key, value);
044            }
045    
046            @Override
047            public Object remove(Object key) {
048                    _names.remove(key);
049    
050                    return super.remove(key);
051            }
052    
053            private final Vector<String> _names;
054    
055    }