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 com.liferay.portal.kernel.bean.BeanPropertiesUtil;
018    
019    import java.io.Serializable;
020    
021    import java.util.Comparator;
022    
023    /**
024     * @author Brian Wing Shun Chan
025     * @author Shuyang Zhou
026     */
027    @SuppressWarnings("rawtypes")
028    public abstract class OrderByComparator implements Comparator, Serializable {
029    
030            @Override
031            public abstract int compare(Object obj1, Object obj2);
032    
033            public String getOrderBy() {
034                    return null;
035            }
036    
037            public String[] getOrderByConditionFields() {
038                    return getOrderByFields();
039            }
040    
041            public Object[] getOrderByConditionValues(Object obj) {
042                    String[] fields = getOrderByConditionFields();
043    
044                    Object[] values = new Object[fields.length];
045    
046                    for (int i = 0; i < fields.length; i++) {
047                            values[i] = BeanPropertiesUtil.getObject(obj, fields[i]);
048                    }
049    
050                    return values;
051            }
052    
053            public String[] getOrderByFields() {
054                    String orderBy = getOrderBy();
055    
056                    if (orderBy == null) {
057                            return null;
058                    }
059    
060                    String[] parts = StringUtil.split(orderBy);
061    
062                    String[] fields = new String[parts.length];
063    
064                    for (int i = 0; i < parts.length; i++) {
065                            String part = parts[i];
066    
067                            int x = part.indexOf(CharPool.PERIOD);
068                            int y = part.indexOf(CharPool.SPACE, x);
069    
070                            if (y == -1) {
071                                    y = part.length();
072                            }
073    
074                            fields[i] = part.substring(x + 1, y);
075                    }
076    
077                    return fields;
078            }
079    
080            public boolean isAscending() {
081                    String orderBy = getOrderBy();
082    
083                    if ((orderBy == null) ||
084                            StringUtil.toUpperCase(orderBy).endsWith(_ORDER_BY_DESC)) {
085    
086                            return false;
087                    }
088                    else {
089                            return true;
090                    }
091            }
092    
093            public boolean isAscending(String field) {
094                    return isAscending();
095            }
096    
097            @Override
098            public String toString() {
099                    return getOrderBy();
100            }
101    
102            private static final String _ORDER_BY_DESC = " DESC";
103    
104    }