java - 未找到当前线程 : Spring 3 and Hibernate 4 (Using @PostConstruct annotation) 的 session

Question

我阅读了大量有类似问题的人的帖子，但我仍然无法使我的代码工作。

当我将 No Session found for current thread 从 Dao 移至服务层时，就会出现“@Transactional ”。事实上，我确信将事务绑定(bind)到单个访问是一种资源浪费。顺便说一下，我的网络应用程序配置非常常见:

• Spring 3.1.2
• hibernate 4

我无法找出问题所在，我检查了著名的 <tx:annotation-driven> 是否位于正确的位置以及正确的 <context:component-scan ...> 。我的猜测是 spring 需要将 @Transactional 也放置在具有 session 工厂引用的类之上，但这对我来说似乎有点不合逻辑。

这是servlet

<!-- auto-detects and registers annotated classes belonging to the base package-->
<context:component-scan base-package="com.x.y.controllers" />
<!-- flips on all the annotation-driven capabilities for Spring MVC -->
<mvc:annotation-driven />   
...

这是上下文

<!-- enables the @Transactional annotantions -->
<tx:annotation-driven transaction-manager="transactionManager"/>

<bean id="transactionManager"
    class="org.springframework.orm.hibernate4.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

<!-- auto-detects and registers annotated classes belonging to the base package-->
<context:component-scan base-package="com.x.y.service" />
<context:component-scan base-package="com.x.y.aop" />
<context:component-scan base-package="com.x.y.model" />


<bean id="dataSource"
class = "com.mchange.v2.c3p0.ComboPooledDataSource"
destroy-method="close">
    <property name="driverClass" value="${database.driver.className}" />
    <property name="jdbcUrl" value="${database.uri}" />
    <property name="user" value="${database.username}" />
    <property name="password" value="${database.password}" />

    <!-- these are C3P0 properties -->       
    <property name="checkoutTimeout" value="30000" />
    <property name="initialPoolSize" value="10" />
    <property name="maxIdleTime" value="30" />
    <property name="minPoolSize" value="10" />
    <property name="maxPoolSize" value="100" />
    <property name="maxStatements" value="200" />
    <property name="testConnectionOnCheckout" value="false" />
    <property name="testConnectionOnCheckin" value="true" />
    <property name="preferredTestQuery" value="SELECT 1" />
    <property name="idleConnectionTestPeriod" value="30" />
</bean> 

<bean id="sessionFactory"
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">${database.hibernate.dialect}</prop>
            <prop key="hibernate.hbm2ddl.auto">update</prop>
            <prop key="hibernate.cache.use_second_level_cache">true</prop>
            <prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</prop>
            <prop key="hibernate.generate_statistics">true</prop>
            <prop key="hibernate.show_sql">false</prop>
            <prop key="hibernate.connection.SetBigStringTryClob">true</prop>
            <prop key="hibernate.jdbc.batch_size">0</prop>          
        </props>
    </property>
</bean>

这是服务

package com.x.y.service.initialization;

@Component
public class Initializer {

    @Autowired
    @Qualifier("userDaoImpl")
    private UserDao userDao;

    @PostConstruct
    @Transactional
    public void init()
    {
        ProfiledUser admin = userDao.loadByUsername("Administrator");

        ...
    }
}

这是DAO

package com.x.y.model.dao;

@Repository(value="userDaoImpl")
public class UserDaoImpl implements UserDao{

    @Autowired
    @Qualifier("sessionFactory")
    protected SessionFactory sessionFactory;

    public ProfiledUser loadByUsername(String username)
    {
        Session session = sessionFactory.getCurrentSession();
        Criteria criteria = session.createCriteria(ProfiledUser.class);
        criteria.add(Restrictions.eq("username", username));
        ProfiledUser user = (ProfiledUser) criteria.uniqueResult();
        if(user != null)
            return user;
        else
            return null;
    }
}

这是堆栈跟踪

ERROR: org.springframework.web.context.ContextLoader - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'initializer': Invocation of init method failed; nested exception is org.hibernate.HibernateException: No Session found for current thread
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:135)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:394)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1448)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:609)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:469)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:383)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:283)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4206)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4705)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
    at org.apache.catalina.core.StandardService.start(StandardService.java:525)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: org.hibernate.HibernateException: No Session found for current thread
    at org.springframework.orm.hibernate4.SpringSessionContext.currentSession(SpringSessionContext.java:97)
    at org.hibernate.internal.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:881)
    at com.x.y.model.dao.UserDaoImpl.loadByUsername(UserDaoImpl.java:37)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
    at com.sun.proxy.$Proxy15.loadByUsername(Unknown Source)
    at com.x.y.service.initialization.Initializer.init(Initializer.java:46)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:346)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:299)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:132)
    ... 29 more

Answer 1

也许它是其他答案所暗示的错误配置，但是请记住，您不应该使用 @Transactional 注释您的 @PostConstruct 并期望它能够工作。当执行 @PostConstruct 时，不能保证您的代码具有事务语义。原因是@PostConstruct仅保证所有依赖项都已注入(inject)并且bean构建已完成，但并不意味着完整的上下文已完成加载(不保证事务工具已完成)已完成)。

如果您确实需要在 @PostConstruct 中进行事务处理，请采用编程方式。这些只是我的两分钱，但很可能是您问题的原因

更新

刚刚找到一个blog关于它，他们建议使用 @PostInitialize 因为它保证在加载完整上下文后被调用