/*
 * Copyright 2002-2008 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.hibernate3;

import org.hibernate.HibernateException;
import org.hibernate.classic.Session;
import org.hibernate.context.CurrentSessionContext;
import org.hibernate.engine.SessionFactoryImplementor;

/**
 * Implementation of Hibernate 3.1's CurrentSessionContext interface
 * that delegates to Spring's SessionFactoryUtils for providing a
 * Spring-managed current Session.
 *
 * <p>Used by Spring's {@link LocalSessionFactoryBean} when told to expose a
 * transaction-aware SessionFactory. This is the default as of Spring 2.5.
 *
 * <p>This CurrentSessionContext implementation can also be specified in custom
 * SessionFactory setup through the "hibernate.current_session_context_class"
 * property, with the fully qualified name of this class as value.
 *
 * @author Juergen Hoeller
 * @since 2.0
 * @see SessionFactoryUtils#doGetSession
 * @see LocalSessionFactoryBean#setExposeTransactionAwareSessionFactory
 */
public class SpringSessionContext implements CurrentSessionContext {

	private final SessionFactoryImplementor sessionFactory;


	/**
	 * Create a new SpringSessionContext for the given Hibernate SessionFactory.
	 * @param sessionFactory the SessionFactory to provide current Sessions for
	 */
	public SpringSessionContext(SessionFactoryImplementor sessionFactory) {
		this.sessionFactory = sessionFactory;
	}


	/**
	 * Retrieve the Spring-managed Session for the current thread, if any.
	 */
	public Session currentSession() throws HibernateException {
		try {
			return (org.hibernate.classic.Session) SessionFactoryUtils.doGetSession(this.sessionFactory, false);
		}
		catch (IllegalStateException ex) {
			throw new HibernateException(ex.getMessage());
		}
	}

}