com.liferay.portal.kernel.util.OrderByComparator.java Source code

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Here is the source code for com.liferay.portal.kernel.util.OrderByComparator.java

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/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.portal.kernel.util;

import com.liferay.petra.string.CharPool;
import com.liferay.portal.kernel.bean.BeanPropertiesUtil;

import java.io.Serializable;

import java.util.Comparator;

/**
 * @author Brian Wing Shun Chan
 * @author Shuyang Zhou
 */
public abstract class OrderByComparator<T> implements Comparator<T>, Serializable {

    public String getOrderBy() {
        return null;
    }

    public String[] getOrderByConditionFields() {
        return getOrderByFields();
    }

    public Object[] getOrderByConditionValues(Object obj) {
        String[] fields = getOrderByConditionFields();

        Object[] values = new Object[fields.length];

        for (int i = 0; i < fields.length; i++) {
            values[i] = BeanPropertiesUtil.getObject(obj, fields[i]);
        }

        return values;
    }

    public String[] getOrderByFields() {
        String orderBy = getOrderBy();

        if (orderBy == null) {
            return null;
        }

        String[] parts = StringUtil.split(orderBy);

        String[] fields = new String[parts.length];

        for (int i = 0; i < parts.length; i++) {
            String part = parts[i];

            int x = part.indexOf(CharPool.PERIOD);

            int y = part.indexOf(CharPool.SPACE, x);

            if (y == -1) {
                y = part.length();
            }

            fields[i] = part.substring(x + 1, y);
        }

        return fields;
    }

    public boolean isAscending() {
        String orderBy = StringUtil.toUpperCase(getOrderBy());

        if ((orderBy == null) || orderBy.endsWith(_ORDER_BY_DESC)) {
            return false;
        }

        return true;
    }

    public boolean isAscending(String field) {
        return isAscending();
    }

    @Override
    public String toString() {
        String orderBy = getOrderBy();

        if (orderBy == null) {
            return super.toString();
        }

        return orderBy;
    }

    private static final String _ORDER_BY_DESC = " DESC";

}