org.ow2.bonita.env.interceptor.DescNullFirstInterceptor.java Source code

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Here is the source code for org.ow2.bonita.env.interceptor.DescNullFirstInterceptor.java

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/**
 * Copyright (C) 2011  BonitaSoft S.A.
 * BonitaSoft, 31 rue Gustave Eiffel - 38000 Grenoble
 * 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
 * version 2.1 of the License.
 * 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.
 * You should have received a copy of the GNU Lesser General Public License along with this
 * program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
 * Floor, Boston, MA  02110-1301, USA.
 **/
package org.ow2.bonita.env.interceptor;

import org.hibernate.EmptyInterceptor;

public abstract class DescNullFirstInterceptor extends EmptyInterceptor {

    private static final long serialVersionUID = -7671847499846010891L;
    final static String ORDER_BY = "order by";

    public String onPrepareStatement(String sql) {
        String query = sql.toLowerCase();
        int orderByIndex = query.indexOf(ORDER_BY);
        if (orderByIndex > -1) {
            int orderByEndIndex = getLast(query, getKeyWordsAfterOrderBy());
            if (orderByEndIndex == -1) {
                orderByEndIndex = query.length();
            }
            String orderByContent = sql.substring(orderByIndex + 9, orderByEndIndex);
            String[] orderByNames = orderByContent.split("\\,");
            for (int i = 0; i < orderByNames.length; i++) {
                String current = orderByNames[i];
                String currentTrim = current.trim();
                if (currentTrim.length() > 0) {
                    String currentLC = currentTrim.toLowerCase();
                    if (currentLC.endsWith(" desc")) {
                        current = current.substring(0, current.length() - 5);
                        orderByNames[i] = getDescValue(current);
                    } else if (currentLC.endsWith(" asc")) {
                        current = current.substring(0, current.length() - 4);
                        orderByNames[i] = getAscValue(current);
                    } else {
                        current = current.substring(0, current.length());
                        orderByNames[i] = getAscValue(current);
                    }
                }
            }
            orderByContent = join(orderByNames, ",");
            sql = formatSelectQuery(sql, orderByIndex, orderByContent, orderByEndIndex);
        }
        return super.onPrepareStatement(sql);
    }

    protected abstract String getDescValue(String current);

    protected abstract String getAscValue(String current);

    protected abstract String[] getKeyWordsAfterOrderBy();

    protected int getLast(final String query, String... list) {
        int result = -1;
        int i = 0;
        int size = list.length;
        while (result == -1 && i < size) {
            result = getLast(query, list[i]);
            i++;
        }
        return result;
    }

    protected int getLast(final String query, String end) {
        return query.indexOf(end);
    }

    protected String formatSelectQuery(String sql, int orderByIndex, String orderByContent, int orderByEndIndex) {
        StringBuilder builder = new StringBuilder(sql.substring(0, orderByIndex));
        builder.append("order by ").append(orderByContent).append(" ").append(sql.substring(orderByEndIndex));
        return builder.toString();
    }

    protected static String join(String[] elements, String join) {
        StringBuilder joinBuilder = new StringBuilder();
        int penultimateIndex = elements.length - 1;
        for (int i = 0; i < penultimateIndex; i++) {
            joinBuilder.append(elements[i]).append(",");
        }
        joinBuilder.append(elements[penultimateIndex]);
        return joinBuilder.toString();
    }

}