org.springframework.orm.toplink.support.TransactionAwareSessionAdapter Maven / Gradle / Ivy
/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.orm.toplink.support;
import oracle.toplink.sessions.Session;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.orm.toplink.SessionFactory;
/**
* This adapter FactoryBean takes a TopLink SessionFactory and exposes a
* corresponding transaction-aware TopLink Session as bean reference.
*
* This adapter bean will usually be defined in front of a Spring
* LocalSessionFactoryBean, to allow for passing Session references to DAOs
* that expect to work on a raw TopLink Session. Your DAOs can then,
* for example, access the currently active Session and UnitOfWork via
* Session.getActiveSession() and
* Session.getActiveUnitOfWork(), respectively.
*
*
The main advantage of this proxy is that it allows DAOs to work with a
* plain TopLink Session reference, while still participating in Spring's
* (or a J2EE server's) resource and transaction management. DAOs will only
* rely on the TopLink API in such a scenario, without any Spring dependencies.
*
*
It is usually preferable to write your TopLink-based DAOs with Spring's
* TopLinkTemplate, offering benefits such as consistent data access exceptions
* instead of TopLinkExceptions at the DAO layer. However, Spring's resource
* and transaction management (and Dependency Injection) will work for DAOs
* written against the plain TopLink API too.
*
*
Of course, you can still access the target TopLink SessionFactory
* even when your DAOs go through this adapter, by defining a bean reference
* that points directly at your target SessionFactory bean.
*
*
Note that the actual creation of a transaction-aware TopLink Session
* is available on the TopLink SessionFactory itself. This adapter FactoryBean
* is just a convenient way to expose such a Session in a declarative fashion.
*
* @author Juergen Hoeller
* @since 1.2
* @see org.springframework.orm.toplink.LocalSessionFactoryBean
* @see org.springframework.orm.toplink.SessionFactory#createTransactionAwareSession()
* @see oracle.toplink.sessions.Session#getActiveSession()
* @see oracle.toplink.sessions.Session#getActiveUnitOfWork()
*/
public class TransactionAwareSessionAdapter implements FactoryBean {
private Session session;
/**
* Set the SessionFactory that this adapter is supposed to expose a
* transaction-aware TopLink Session for. This should be the raw
* SessionFactory, as accessed by TopLinkTransactionManager.
* @see org.springframework.orm.toplink.TopLinkTransactionManager
*/
public void setSessionFactory(SessionFactory sessionFactory) {
this.session = sessionFactory.createTransactionAwareSession();
}
public Object getObject() {
return this.session;
}
public Class getObjectType() {
return Session.class;
}
public boolean isSingleton() {
return true;
}
}