解决JPA延迟加载错误问题

 一：(Spring + Struts + JPA)解决办法

 

在entity中的@OneToMany、@OneToOne等中设置fetch = FetchType.LAZY 时，在Struts2的Action中进行相关操作出现错误信息如下
org.hibernate.LazyInitializationException异常

解决方法：

 

在web.xml中加入以下代码：注意必须Struts配置文件的书写顺序 ，必须放到FIlterDispatcher之前

 

 <filter> <filter-name>jpaFilter</filter-name> <filter-class> org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter </filter-class> </filter> <filter-mapping> <filter-name>jpaFilter</filter-name> <url-pattern>*.action</url-pattern> </filter-mapping>

 

 

二：SpringMVC +JPA防止延迟加载错误的解决办法:

 

配置文件如下

 

 

 

<bean name="openEntityManagerInViewInterceptor" class="org.springframework.orm.jpa.support.OpenEntityManagerInViewInterceptor"> <property name="entityManagerFactory"> <ref bean="entityManagerFactory"/> <property> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver" > <property name="prefix" value ="/WEB-INF/jsp/" /> <property name="suffix" value =".jsp" /> </bean> <bean id="simpleUrlHandlerMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping" > <property name ="interceptors"> <list> <ref bean ="openEntityManagerInViewInterceptor" /> </list> </property> <property name ="mappings"> <props> <prop key="hello.html"> helloController </prop> <prop key="login.html" > loginAction </prop> <prop key="userManager.html" > userController </prop> <prop key="userList.html" > userListController </prop > </props> </property> </bean>