/*
* Copyright (C) 2009 eXo Platform SAS.
*
* This 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 software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.exoplatform.services.organization.jdbc;
import org.exoplatform.commons.utils.ListAccess;
import org.exoplatform.services.database.DAO;
import org.exoplatform.services.database.DBObject;
import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
/**
* Created by The eXo Platform SAS.
*
* @author <a href="mailto:anatoliy.bazko@exoplatform.com.ua">Anatoliy Bazko</a>
* @version $Id: JDBCUserListAccess.java 111 2008-11-11 11:11:11Z $
* @param <E>
*/
public class JDBCListAccess<E> implements ListAccess<E>
{
/**
* The DAO.
*/
protected DAO dao;
/**
* The find query string.
*/
protected String findQuery;
/**
* The count query string.
*/
protected String countQuery;
/**
* JDBCUserListAccess constructor.
*
* @param dao
* The DAO
* @param findQuery
* Find query string
* @param countQuery
* Count query string
*/
public JDBCListAccess(DAO dao, String findQuery, String countQuery)
{
this.dao = dao;
this.findQuery = findQuery;
this.countQuery = countQuery;
}
/**
* {@inheritDoc}
*/
public int getSize() throws Exception
{
Connection connection = null;
try
{
connection = dao.getExoDatasource().getConnection();
Object retObj = dao.loadDBField(countQuery);
if (retObj instanceof Integer)
{
return ((Integer)retObj).intValue();
}
else if (retObj instanceof BigDecimal)
{
return ((BigDecimal)retObj).intValue();
}
else
{
return ((Long)retObj).intValue();
}
}
finally
{
dao.getExoDatasource().closeConnection(connection);
}
}
/**
* {@inheritDoc}
*/
public E[] load(int index, int length) throws Exception, IllegalArgumentException
{
Statement statement = null;
ResultSet resultSet = null;
Connection connection = dao.getExoDatasource().getConnection();
try
{
if (index < 0)
{
throw new IllegalArgumentException("Illegal index: index must be a positive number");
}
if (length < 0)
{
throw new IllegalArgumentException("Illegal length: length must be a positive number");
}
E[] entities = null;
statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
resultSet = statement.executeQuery(findQuery);
for (int p = 0, counter = 0; counter < length; p++)
{
if (!resultSet.next())
throw new IllegalArgumentException(
"Illegal index or length: sum of the index and the length cannot be greater than the list size");
DBObject bean = dao.createInstance();
dao.getDBObjectMapper().mapResultSet(resultSet, bean);
if (p >= index)
{
if (entities == null)
{
entities = (E[])Array.newInstance(bean.getClass(), length);
}
entities[counter++] = (E)bean;
}
}
return entities == null ? (E[])new Object[0] : entities;
}
finally
{
if (resultSet != null)
{
resultSet.close();
}
if (statement != null)
{
statement.close();
}
dao.getExoDatasource().closeConnection(connection);
}
}
}