01: /*
02: * Copyright 2002-2006 the original author or authors.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16:
17: package org.springframework.orm.hibernate3;
18:
19: import java.sql.SQLException;
20:
21: import org.hibernate.HibernateException;
22: import org.hibernate.Session;
23:
24: /**
25: * Callback interface for Hibernate code. To be used with {@link HibernateTemplate}'s
26: * execution methods, often as anonymous classes within a method implementation.
27: * A typical implementation will call <code>Session.load/find/update</code> to perform
28: * some operations on persistent objects. It can also perform direct JDBC operations
29: * via Hibernate's <code>Session.connection()</code>, operating on a JDBC Connection.
30: *
31: * <p>Note that Hibernate works on unmodified plain Java objects, performing dirty
32: * detection via copies made at load time. Returned objects can thus be used outside
33: * of an active Hibernate Session without any hassle, e.g. for display in a web GUI.
34: * Reassociating such instances with a new Session, e.g. for updates when coming
35: * back from the GUI, is straightforward, as the instance has kept its identity.
36: * You should care to reassociate them as early as possible though, to avoid having
37: * already loaded a version from the database in the same Session.
38: *
39: * @author Juergen Hoeller
40: * @since 1.2
41: * @see HibernateTemplate
42: * @see HibernateTransactionManager
43: */
44: public interface HibernateCallback {
45:
46: /**
47: * Gets called by <code>HibernateTemplate.execute</code> with an active
48: * Hibernate <code>Session</code>. Does not need to care about activating
49: * or closing the <code>Session</code>, or handling transactions.
50: *
51: * <p>If called without a thread-bound Hibernate transaction (initiated
52: * by HibernateTransactionManager), the code will simply get executed on the
53: * underlying JDBC connection with its transactional semantics. If Hibernate
54: * is configured to use a JTA-aware DataSource, the JDBC connection and thus
55: * the callback code will be transactional if a JTA transaction is active.
56: *
57: * <p>Allows for returning a result object created within the callback,
58: * i.e. a domain object or a collection of domain objects.
59: * A thrown custom RuntimeException is treated as an application exception:
60: * It gets propagated to the caller of the template.
61: *
62: * @param session active Hibernate session
63: * @return a result object, or <code>null</code> if none
64: * @throws HibernateException if thrown by the Hibernate API
65: * @throws SQLException if thrown by Hibernate-exposed JDBC API
66: * @see HibernateTemplate#execute
67: * @see HibernateTemplate#executeFind
68: */
69: Object doInHibernate(Session session) throws HibernateException,
70: SQLException;
71:
72: }
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