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Java > Open Source Codes > org > jboss > ejb > plugins > cmp > jdbc > JDBCFindEntityCommand


1 /*
2 * JBoss, Home of Professional Open Source
3 * Copyright 2005, JBoss Inc., and individual contributors as indicated
4 * by the @authors tag. See the copyright.txt in the distribution for a
5 * full listing of individual contributors.
6 *
7 * This is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU Lesser General Public License as
9 * published by the Free Software Foundation; either version 2.1 of
10 * the License, or (at your option) any later version.
11 *
12 * This software is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this software; if not, write to the Free
19 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21 */
22 package org.jboss.ejb.plugins.cmp.jdbc;
23
24 import java.lang.reflect.Method JavaDoc;
25 import java.util.Collection JavaDoc;
26
27 import javax.ejb.FinderException JavaDoc;
28 import javax.ejb.ObjectNotFoundException JavaDoc;
29
30 import org.jboss.ejb.EntityEnterpriseContext;
31 import org.jboss.ejb.GenericEntityObjectFactory;
32
33 /**
34  * JDBCFindEntityCommand finds a single entity, by deligating to
35  * find entities and checking that only entity is returned.
36  *
37  * @author <a HREF="mailto:dain@daingroup.com">Dain Sundstrom</a>
38  * @author <a HREF="mailto:rickard.oberg@telkel.com">Rickard Öberg</a>
39  * @author <a HREF="mailto:marc.fleury@telkel.com">Marc Fleury</a>
40  * @author <a HREF="mailto:shevlandj@kpi.com.au">Joe Shevland</a>
41  * @author <a HREF="mailto:justin@j-m-f.demon.co.uk">Justin Forder</a>
42  * @version $Revision: 37459 $
43  */
44 public final class JDBCFindEntityCommand
45 {
46    private static final String JavaDoc NO_SUCH_ENTITY = "No such entity!";
47
48    private final JDBCStoreManager manager;
49
50    public JDBCFindEntityCommand(JDBCStoreManager manager)
51    {
52       this.manager = manager;
53    }
54
55    public Object JavaDoc execute(Method JavaDoc finderMethod, Object JavaDoc[] args, EntityEnterpriseContext ctx, GenericEntityObjectFactory factory)
56       throws FinderException JavaDoc
57    {
58
59       JDBCQueryCommand query = manager.getQueryManager().getQueryCommand(finderMethod);
60
61       Collection JavaDoc result = query.execute(finderMethod, args, ctx, factory);
62       if(result.isEmpty())
63       {
64          throw new ObjectNotFoundException JavaDoc(NO_SUCH_ENTITY);
65       }
66       else if(result.size() == 1)
67       {
68          return result.iterator().next();
69       }
70       else
71       {
72          throw new FinderException JavaDoc("More than one entity matches the finder criteria: " + result);
73       }
74    }
75 }
76
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