org.springframework.orm.toplink.AbstractSessionFactory 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;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import oracle.toplink.exceptions.TopLinkException;
import oracle.toplink.sessions.Session;
import oracle.toplink.sessions.UnitOfWork;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Abstract SessionFactory implementation that creates proxies for
* "managed" client Sessions and transaction-aware Session references.
*
* Delegates to two template methods:
*
* @author Juergen Hoeller
* @since 1.2.6
* @see #getMasterSession()
* @see #createClientSession()
*/
public abstract class AbstractSessionFactory implements SessionFactory {
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
/**
* Create a plain client Session for this factory's master Session.
* @see #createClientSession()
*/
public Session createSession() throws TopLinkException {
logger.debug("Creating TopLink client Session");
return createClientSession();
}
/**
* Create a "managed" client Session reference for an underlying
* client Session created for this factory.
* @see #createClientSession()
*/
public Session createManagedClientSession() throws TopLinkException {
logger.debug("Creating managed TopLink client Session");
return (Session) Proxy.newProxyInstance(
getClass().getClassLoader(), new Class[] {Session.class},
new ManagedClientInvocationHandler(createClientSession()));
}
/**
* Create a transaction-aware Session reference for this factory's master Session,
* expecting transactions to be registered for this SessionFactory.
* @see #getMasterSession()
* @see oracle.toplink.sessions.Session#getActiveSession()
* @see oracle.toplink.sessions.Session#getActiveUnitOfWork()
*/
public Session createTransactionAwareSession() throws TopLinkException {
logger.debug("Creating transaction-aware TopLink Session");
return createTransactionAwareSession(this);
}
/**
* Create a transaction-aware Session reference for this factory's master Session,
* expecting transactions to be registered for the given SessionFactory.
*
This method is public to allow custom SessionFactory facades to access
* it directly, if necessary.
* @param sessionFactory the SessionFactory that transactions
* are expected to be registered for
* @see #getMasterSession()
* @see oracle.toplink.sessions.Session#getActiveSession()
* @see oracle.toplink.sessions.Session#getActiveUnitOfWork()
*/
public Session createTransactionAwareSession(SessionFactory sessionFactory) throws TopLinkException {
return (Session) Proxy.newProxyInstance(
getClass().getClassLoader(), new Class[] {Session.class},
new TransactionAwareInvocationHandler(sessionFactory, getMasterSession()));
}
/**
* Return this factory's "master" Session.
* For example, a TopLink ServerSession.
*
Used for creating transaction-aware Session reference.
*/
protected abstract Session getMasterSession();
/**
* Create a new client Session for this factory's master Session.
* For example, a TopLink ClientSession.
*
Used for creating plain Sessions and "managed" client Sessions.
* @throws TopLinkException if creation of a client Session failed
*/
protected abstract Session createClientSession() throws TopLinkException;
/**
* Invocation handler that decorates a client Session with an "active"
* UnitOfWork. For use in situations where Spring's TopLinkTransactionManager
* requires a "managed" thread-safe TopLink Session.
*/
private static class ManagedClientInvocationHandler implements InvocationHandler {
private final Session target;
private final UnitOfWork uow;
public ManagedClientInvocationHandler(Session target) {
this.target = target;
this.uow = this.target.acquireUnitOfWork();
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if (method.getName().equals("getActiveSession")) {
return this.target;
}
else if (method.getName().equals("getActiveUnitOfWork")) {
return this.uow;
}
else if (method.getName().equals("release")) {
this.uow.release();
this.target.release();
}
else if (method.getName().equals("equals")) {
// Only consider equal when proxies are identical.
return (proxy == args[0] ? Boolean.TRUE : Boolean.FALSE);
}
else if (method.getName().equals("hashCode")) {
// Use hashCode of SessionFactory proxy.
return new Integer(hashCode());
}
// Invoke method on target Session.
try {
return method.invoke(this.target, args);
}
catch (InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}
/**
* Invocation handler that delegates getActiveSession calls
* to SessionFactoryUtils, for being aware of thread-bound transactions.
*/
private static class TransactionAwareInvocationHandler implements InvocationHandler {
private final SessionFactory sessionFactory;
private final Session target;
public TransactionAwareInvocationHandler(SessionFactory sessionFactory, Session target) {
this.sessionFactory = sessionFactory;
this.target = target;
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
// Invocation on Session interface coming in...
if (method.getName().equals("getActiveSession")) {
// Handle getActiveSession method: return transactional Session, if any.
try {
return SessionFactoryUtils.doGetSession(this.sessionFactory, false);
}
catch (IllegalStateException ex) {
// getActiveSession is supposed to return the Session itself if no active one found.
return this.target;
}
}
else if (method.getName().equals("getActiveUnitOfWork")) {
// Handle getActiveUnitOfWork method: return transactional UnitOfWork, if any.
try {
return SessionFactoryUtils.doGetSession(this.sessionFactory, false).getActiveUnitOfWork();
}
catch (IllegalStateException ex) {
// getActiveUnitOfWork is supposed to return null if no active one found.
return null;
}
}
else if (method.getName().equals("equals")) {
// Only consider equal when proxies are identical.
return (proxy == args[0] ? Boolean.TRUE : Boolean.FALSE);
}
else if (method.getName().equals("hashCode")) {
// Use hashCode of SessionFactory proxy.
return new Integer(hashCode());
}
// Invoke method on target Session.
try {
return method.invoke(this.target, args);
}
catch (InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}
}