001    /**
002     * Copyright (c) 2000-2013 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.io.Serializable;
018    
019    import java.util.Comparator;
020    
021    /**
022     * @author Hugo Huijser
023     */
024    public class NumericalStringComparator
025            implements Comparator<String>, Serializable {
026    
027            public NumericalStringComparator() {
028                    this(true, false);
029            }
030    
031            public NumericalStringComparator(boolean ascending, boolean caseSensitive) {
032                    _ascending = ascending;
033                    _caseSensitive = caseSensitive;
034            }
035    
036            @Override
037            public int compare(String s1, String s2) {
038                    if (s1 == null) {
039                            s1 = StringPool.BLANK;
040                    }
041    
042                    if (s2 == null) {
043                            s2 = StringPool.BLANK;
044                    }
045    
046                    int startsWithWeight = StringUtil.startsWithWeight(s1, s2);
047    
048                    boolean lastMatchingCharIsDigit = false;
049    
050                    if ((startsWithWeight > 0) &&
051                            Validator.isDigit(s1.charAt(startsWithWeight - 1))) {
052    
053                            lastMatchingCharIsDigit = true;
054                    }
055    
056                    s1 = s1.substring(startsWithWeight);
057                    s2 = s2.substring(startsWithWeight);
058    
059                    String leadingDigits1 = StringUtil.extractLeadingDigits(s1);
060                    String leadingDigits2 = StringUtil.extractLeadingDigits(s2);
061    
062                    int value = 0;
063    
064                    if ((lastMatchingCharIsDigit &&
065                             (Validator.isNotNull(leadingDigits1) ||
066                              Validator.isNotNull(leadingDigits2))) ||
067                            (Validator.isNotNull(leadingDigits1) &&
068                             Validator.isNotNull(leadingDigits2))) {
069    
070                            if (leadingDigits1.length() != leadingDigits2.length()) {
071                                    value = leadingDigits1.length() - leadingDigits2.length();
072                            }
073                            else {
074                                    int i1 = GetterUtil.getInteger(leadingDigits1);
075                                    int i2 = GetterUtil.getInteger(leadingDigits2);
076    
077                                    value = i1 - i2;
078                            }
079                    }
080                    else {
081                            if (_caseSensitive) {
082                                    value = s1.compareTo(s2);
083                            }
084                            else {
085                                    value = s1.compareToIgnoreCase(s2);
086                            }
087                    }
088    
089                    if (_ascending) {
090                            return value;
091                    }
092                    else {
093                            return -value;
094                    }
095            }
096    
097            private boolean _ascending;
098            private boolean _caseSensitive;
099    
100    }