java.lang.IllegalStateException：没有Hibernate会话绑定到线程,并且配置不允许创建非事务性

这是我的JUnit类：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"/applicationContext.xml"})
@TransactionConfiguration(transactionManager="transactionManager")
@Transactional
public class MyTest {
    @Qualifier("session")
    @Autowired
    private Session session;

    @Test
    public void testSomething() {
        session.get(User.class,"me@here.com");
    }
}

如果我@Autowire一个SessionFactory并以编程方式获取我的会话(而不是在Spring XML中定义它),每一个都可以正常工作：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"/applicationContext.xml"})
@TransactionConfiguration(transactionManager="transactionManager")
@Transactional
public class MyTest{    
    @Qualifier("sessionFactory")
    @Autowired
    private SessionFactory sessionFactory;

    @Test
    public void testSomething() {
    Session session = SessionFactoryUtils.getSession(sessionFactory,false);
        session.get(User.class,"me@here.com");
    }
}

但是,如果我使用< aop：scoped-proxy />在我的Spring XML中定义了我的会话,我可以让我的原始示例工作.像这样：

<?xml version="1.0" encoding="UTF-8"?>

<beans  xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-2.5.xsd
        http://www.springframework.org/schema/aop 
        http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
        ">

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        ...
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionfactorybean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation"><value>classpath:/hibernate.cfg.xml</value></property>
        <property name="configurationClass">
            <value>org.hibernate.cfg.AnnotationConfiguration</value>
        </property>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
        <property name="dataSource" ref="dataSource" />
    </bean>

    <tx:annotation-driven transaction-manager="transactionManager"/>

    <bean id="session" class="org.springframework.orm.hibernate3.SessionFactoryUtils" factory-method="getSession" scope="prototype">
        <constructor-arg ref="sessionFactory" />
        <constructor-arg value="false" />
        <!-- This is seems to be needed to get rid of the 'No Hibernate Session' error' -->
        <aop:scoped-proxy />
    </bean>
</beans>

我的问题是：为什么< aop：scoped-proxy />需要考虑到在单元测试中应该只有一个线程有限的事务上下文？什么是定义我的Hibernate Session bean的正确方法？