01: /*
02: * JBoss, Home of Professional Open Source.
03: * Copyright 2006, Red Hat Middleware LLC, and individual contributors
04: * as indicated by the @author tags. See the copyright.txt file in the
05: * distribution for a full listing of individual contributors.
06: *
07: * This is free software; you can redistribute it and/or modify it
08: * under the terms of the GNU Lesser General Public License as
09: * 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;
25: import java.util.Collection;
26:
27: import javax.ejb.FinderException;
28: import javax.ejb.ObjectNotFoundException;
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: 57209 $
43: */
44: public final class JDBCFindEntityCommand {
45: private static final String NO_SUCH_ENTITY = "No such entity!";
46:
47: private final JDBCStoreManager manager;
48:
49: public JDBCFindEntityCommand(JDBCStoreManager manager) {
50: this .manager = manager;
51: }
52:
53: public Object execute(Method finderMethod, Object[] args,
54: EntityEnterpriseContext ctx,
55: GenericEntityObjectFactory factory) throws FinderException {
56:
57: JDBCQueryCommand query = manager.getQueryManager()
58: .getQueryCommand(finderMethod);
59:
60: Collection result = query.execute(finderMethod, args, ctx,
61: factory);
62: if (result.isEmpty()) {
63: throw new ObjectNotFoundException(NO_SUCH_ENTITY);
64: } else if (result.size() == 1) {
65: return result.iterator().next();
66: } else {
67: throw new FinderException(
68: "More than one entity matches the finder criteria: "
69: + result);
70: }
71: }
72: }
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