ui:repeat inside a ui:repeat and LazyInitException

问题

I'm currently experiencing a LazyInitException with a page containing code like the following:

<h:form>
<ui:repeat value="#{searchBean.storiesByTag}" var="iStory">
<ui:repeat value="{iStory.tags}"var="iTag">      
<!-- Lazy init exception here -->
#{iTag.content}
</ui:repeat>
</ui:repeat>
</h:form>

storiesByTag() is a bean method that retrieves a List of stories. The second ui:repeat is supposed to then take each tag and display it's content. All fetching is lazy by default to avoid loading more objects than is necessary.

I'm still fuzzy on this but, from what I understand, this can happen because an EntityManager is closed (exit from @Transactional cloud) during a request or a Collection is being accessed.

Spring's OpenEntityManagerInViewFilter from Spring has been added to the project but I'm not sure if it's doing it's job correctly. Any suggestions for testing this are welcome.

Since I assume the Collection is the problem here I'd like to know what would be a good solution. Should I modify a DAO method with a fetch join? Or should I take the hacky route by using <f:view beforePhaseListener=...> to trigger a method inside a bean and get some fresh Tag objects from the database?

Edit: For Bozho:

web.xml:

<!-- Open EM in View Filter -->

<filter>
    <filter-name>Spring OpenEntityManagerInViewFilter</filter-name>
    <filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
</filter>

<filter-mapping>
<filter-name>Spring OpenEntityManagerInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- End -->

For Roman:

applicationContext.xml:

<!-- Transaction manager for a single JPA EntityManagerFactory (alternative to JTA) -->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" 
        p:entityManagerFactory-ref="entityManagerFactory"/>

回答1:

What is the name of your entity manager factory?

From OpenEntityManagerInView docs:

Looks up the EntityManagerFactory in Spring's root web application context. Supports a "entityManagerFactoryBeanName" filter init-param in web.xml; the default bean name is "entityManagerFactory".

If you specified the name different from "entityManagerFactory" then the filter doesn't see your factory.

来源：https://stackoverflow.com/questions/2385858/uirepeat-inside-a-uirepeat-and-lazyinitexception

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java

exception

jsf

transactional