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LazyInitializationException，即使使用OpenEntityManagerInViewFilter

本文介绍了LazyInitializationException，即使使用OpenEntityManagerInViewFilter的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我试图使用OpenEntityManageInViewFilter，但我一直有LazyInitializationException。人们在EntityManager初始化两次时遇到了类似的问题 - 但这似乎不是我的情况。在异常日志中，我可以看到，过滤器正确启动。

I am trying to use OpenEntityManageInViewFilter, but I keep having the LazyInitializationException. People had similar problems when having the EntityManager initialized twice - but that seems not to be my case. In the exception log I can see, that the Filter is correctly firing.

web.xml：

<web-app version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://java.sun.com/xml/ns/j2ee
        http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <servlet>
        <servlet-name>web-application</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>web-application</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>WEB-INF/web-application-servlet.xml</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

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

    <filter-mapping>
        <filter-name>openEntityManageInViewFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

web-application-servlet.xml

web-application-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-3.1.xsd
            http://www.springframework.org/schema/tx
            http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">

    <import resource="classpath:applicationContext.xml"/>
    <context:property-placeholder location="classpath:application.properties"/>

    <bean id="viewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
        <property name="viewNames" value="*" />
        <property name="cache" value="false"/>
        <property name="prefix" value=""/>
        <property name="suffix" value=".ftl"/>
        <property name="exposeSpringMacroHelpers" value="false"/>
    </bean>

    <bean id="handlerAdapter" autowire="byType" class="org.maite.controller.router.HandlerAdapter" />
    <bean id="handlerMapping" autowire="byType" class="org.maite.controller.router.HandlerMapping" />
</beans>

applicationContext.xml

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-3.1.xsd
            http://www.springframework.org/schema/tx
            http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">


    <tx:annotation-driven />
    <context:annotation-config/>
    <context:spring-configured/>

    <bean id="entityManagerFactory"
          class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="persistenceUnitName" value="persistenceUnit"/>
    </bean>

    <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
</beans>

异常（您可以看到OpenEntityManagerInView占用了堆栈跟踪）：

And the exception (you can see that the OpenEntityManagerInView takes part of the stack trace):

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: org.goout.model.Event.schedule, no session or session was closed
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:894)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:147)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
root cause

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: org.goout.model.Event.schedule, no session or session was closed
    org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:393)
    org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:385)
    org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:378)
    org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:112)
    org.hibernate.collection.internal.PersistentSet.toArray(PersistentSet.java:188)
    java.util.ArrayList.<init>(ArrayList.java:151)
    freemarker.template.SimpleSequence.<init>(SimpleSequence.java:162)
    freemarker.template.DefaultObjectWrapper.wrap(DefaultObjectWrapper.java:117)
    freemarker.template.WrappingTemplateModel.wrap(WrappingTemplateModel.java:134)
    freemarker.template.SimpleHash.get(SimpleHash.java:224)
    freemarker.core.Dot._getAsTemplateModel(Dot.java:76)
    freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
    freemarker.core.IteratorBlock.accept(IteratorBlock.java:94)
    freemarker.core.Environment.visit(Environment.java:221)
    freemarker.core.MixedContent.accept(MixedContent.java:92)
    freemarker.core.Environment.visit(Environment.java:221)
    freemarker.core.Environment.visit(Environment.java:310)
    freemarker.core.BlockAssignment.accept(BlockAssignment.java:83)
    freemarker.core.Environment.visit(Environment.java:221)
    freemarker.core.MixedContent.accept(MixedContent.java:92)
    freemarker.core.Environment.visit(Environment.java:221)
    freemarker.core.Environment.process(Environment.java:199)
    freemarker.template.Template.process(Template.java:237)
    org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:366)
    org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:283)
    org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:233)
    org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167)
    org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:262)
    org.maite.DispatcherServlet.doService(DispatcherServlet.java:38)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:147)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)


推荐答案

您遇到的问题与，这意味着你有2个EntityManager bean - 这是造成混乱。

You have the same problem as described in this question, which means you have 2 EntityManager beans - this is causing the confusion.

基本上，您需要删除

Basically you need to remove the

<import resource="classpath:applicationContext.xml"/>

from web-application-context.ml ，对你的bean进行分区，使得Web层和应用程序bean位于不同的上下文文件中，并确保你的组件在每个扫描文件中挑选正确的bean。这可能需要将类移动到不同的包中，如果没有关于项目结构的更多信息，很难提供建议。

from web-application-context.ml, partition your beans such that web-tier and application beans are in separate context files and make sure your component scan in each picks up the correct beans. This might require moving classes into different packages, difficult to advise without more information about the structure of your project.

最后从web.xml引用两个上下文

Finally reference both contexts from web.xml

这篇关于LazyInitializationException，即使使用OpenEntityManagerInViewFilter的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！

10-23 21:59
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