可见事务管理器的初始化并没有做太多工作。那么看事务管理对其的影响，先看调用栈
TransactionSynchronizationManager.initSynchronization() line: 269
HibernateTransactionManager(AbstractPlatformTransactionManager).prepareSynchronization(DefaultTransactionStatus， TransactionDefinition) line: 542
HibernateTransactionManager(AbstractPlatformTransactionManager).prepareTransactionStatus(TransactionDefinition， Object， boolean， boolean， boolean， Object) line: 513
HibernateTransactionManager(AbstractPlatformTransactionManager).getTransaction(TransactionDefinition) line: 393
TransactionInterceptor(TransactionAspectSupport).createTransactionIfNecessary(PlatformTransactionManager， TransactionAttribute， String) line: 426
TransactionInterceptor(TransactionAspectSupport).invokeWithinTransaction(Method， Class<?>， InvocationCallback) line: 275
TransactionInterceptor.invoke(MethodInvocation) line: 96
ReflectiveMethodInvocation.proceed() line: 179
ExposeInvocationInterceptor.invoke(MethodInvocation) line: 92
ReflectiveMethodInvocation.proceed() line: 179
JdkDynamicAopProxy.invoke(Object， Method， Object[]) line: 213
$Proxy316.getOrderById(String) line: not available
OrderController.orderPay(String， Model) line: 84
　　从调用栈可以看出，只要在连接点处配置了事务管理，首先都会走到initSynchronization()。
/**
* Activate transaction synchronization for the current thread.
* Called by a transaction manager on transaction begin.
* @throws IllegalStateException if synchronization is already active
*/
public static void initSynchronization() throws IllegalStateException {
if (isSynchronizationActive()) {
throw new IllegalStateException("Cannot activate transaction synchronization - already active");
}
logger.trace("Initializing transaction synchronization");
synchronizations.set(new LinkedHashSet<TransactionSynchronization>());
}
　　终会在synchronizations中set进new LinkedHashSet<TransactionSynchronization>()，从而isSynchronizationActive()为true
/**
* Return if transaction synchronization is active for the current thread.
* Can be called before register to avoid unnecessary instance creation.
* @see #registerSynchronization
*/
public static boolean isSynchronizationActive() {
return (synchronizations.get() != null);
}
　　因此这里也解释了上上篇留下的疑问，为什么配置了事务管理，不会抛异常了。其实只有配置了事务，session会在事务提交或者回滚后关闭
SessionImpl.close() line: 402
SessionFactoryUtils.closeSession(Session) line: 167
SpringSessionSynchronization.afterCompletion(int) line: 138
TransactionSynchronizationUtils.invokeAfterCompletion(List<TransactionSynchronization>， int) line: 168
HibernateTransactionManager(AbstractPlatformTransactionManager).invokeAfterCompletion(List<TransactionSynchronization>， int) line: 1001
HibernateTransactionManager(AbstractPlatformTransactionManager).triggerAfterCompletion(DefaultTransactionStatus， int) line: 976
HibernateTransactionManager(AbstractPlatformTransactionManager).processCommit(DefaultTransactionStatus) line: 806
HibernateTransactionManager(AbstractPlatformTransactionManager).commit(TransactionStatus) line: 730
TransactionInterceptor(TransactionAspectSupport).commitTransactionAfterReturning(TransactionAspectSupport$TransactionInfo) line: 483
TransactionInterceptor(TransactionAspectSupport).invokeWithinTransaction(Method， Class<?>， InvocationCallback) line: 290
TransactionInterceptor.invoke(MethodInvocation) line: 96
ReflectiveMethodInvocation.proceed() line: 179
ExposeInvocationInterceptor.invoke(MethodInvocation) line: 92
ReflectiveMethodInvocation.proceed() line: 179
JdkDynamicAopProxy.invoke(Object， Method， Object[]) line: 213
$Proxy316.getOrderById(String) line: not available
OrderController.orderPayInfo(String， Model) line: 72