Using a DAO on a Bean used by a Spring Scheduled Task

I'm developing a web application using Struts2 + Spring, and now I'm trying to add a scheduled task. I'm using Spring's task scheduling to do so. In my applicationContext I have:

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
...
</bean>

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
            <property name="database" value="MYSQL" />
        </bean>
    </property>
</bean>

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

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

And then I have my DAO that uses this entityManagerFactory:

<bean id="dao" class="data.GenericDAO" />

So this works flawlessly within the web application. But now I have a problem when creating the scheduled task:

<task:scheduled-tasks scheduler="notifier">
    <task:scheduled ref="emailService" method="sendMail" fixed-rate="30000" /> 
</task:scheduled-tasks>

<task:scheduler id="notifier" pool-size="10" />

<bean id="emailService" class="services.emailService" >
    <property name="dao" ref="dao" />
</bean>

This executes the method sendMail on my emailService class every 30 seconds. And my emailService has the DAO injected correctly. The thing is that I can fetch objects with my DAO using the findById named queries, but when I try to access any property mapped by Hibernate, such as related collections or entities, I get an "LazyInitializationException: could not initialize proxy - no Session ". I don't know what's wrong, since I believe the scheduled task is being managed by Spring, so it should have no problem using a Spring managed DAO. I must say that I'm using the openSessionInView filter on my struts actions, so maybe I need something similar for this scheduled task.

开发者_如何学C

Any help or suggestion will be appreciated, thanks!

Edit: Finally I found a way to fix this. I changed my regular Dao with one where I can decide when to start and commit the transaction. So before doing anything I start a transaction and then everything works OK. So I still don't know exactly what causes the problem and if someday I'll be able to use my regular DAO, for the moment I'm staying with this solution.

---

OpenSessionInView won't help you, because you don't have a web context. You need Spring's Declarative Transaction Management.

In most cases, what you need to do is just this XML:

<!-- JPA, not hibernate -->
<bean id="myTxManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>      

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

<!-- without backing interfaces you probably also need this: -->
<aop:config proxy-target-class="true">

(Annotate your EmailService class as @Transactional to enable this)