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Java > Open Source Codes > net > sf > jasperreports > engine > data > JRHibernateScrollDataSource


1 /*
2  * ============================================================================
3  * GNU Lesser General Public License
4  * ============================================================================
5  *
6  * JasperReports - Free Java report-generating library.
7  * Copyright (C) 2001-2006 JasperSoft Corporation http://www.jaspersoft.com
8  *
9  * This library is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
22  *
23  * JasperSoft Corporation
24  * 303 Second Street, Suite 450 North
25  * San Francisco, CA 94107
26  * http://www.jaspersoft.com
27  */
28 package net.sf.jasperreports.engine.data;
29
30 import org.hibernate.ScrollableResults;
31
32 import net.sf.jasperreports.engine.JRException;
33 import net.sf.jasperreports.engine.JRRewindableDataSource;
34 import net.sf.jasperreports.engine.query.JRHibernateQueryExecuter;
35
36 /**
37  * Hibernate data source that uses <code>org.hibernate.Query.scroll()</code>.
38  *
39  * @author Lucian Chirita (lucianc@users.sourceforge.net)
40  * @version $Id: JRHibernateScrollDataSource.java 1229 2006-04-19 13:27:35 +0300 (Wed, 19 Apr 2006) teodord $
41  */
42 public class JRHibernateScrollDataSource extends JRHibernateAbstractDataSource implements JRRewindableDataSource
43 {
44     private ScrollableResults scrollableResults;
45
46     public JRHibernateScrollDataSource(JRHibernateQueryExecuter queryExecuter, boolean useFieldDescription)
47     {
48         super(queryExecuter, useFieldDescription, true);
49
50         scrollableResults = queryExecuter.scroll();
51     }
52
53     public boolean next() throws JRException
54     {
55         if (scrollableResults != null && scrollableResults.next())
56         {
57             setCurrentRowValue(scrollableResults.get());
58             return true;
59         }
60         
61         return false;
62     }
63
64     public void moveFirst()
65     {
66         queryExecuter.closeScrollableResults();
67         scrollableResults = queryExecuter.scroll();
68     }
69 }
70
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