延时加载问题解决OpenSessionInViewInterceptor 和 OpenSessionInViewFilter的配置
Open Session In View提供了一种简便的方法,较好地解决了lazy loading问题.
它有两种配置方式OpenSessionInViewInterceptor和OpenSessionInViewFilter(具体参看 SpringSide),功能相同,只是一个在web.xml配置,另一个在application.xml配置而已。
Open Session In View在request把session绑定到当前thread期间一直保持hibernate session在open状态,使session在request的整个期间都可以使用,如在View层里PO也可以lazy loading数据,如 ${ company.employees }。当View 层逻辑完成后,才会通过Filter的doFilter方法或Interceptor的postHandle方法自动关闭session。
OpenSessionInViewInterceptor配置:
<beans>
<bean name="openSessionInViewInterceptor" class="org.springframework.orm.hibernate3.support.OpenSessionInViewInterceptor">
<property name="sessionFactory">
<ref bean="sessionFactory"/>
</property>
</bean>
<bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="interceptors">
<list>
<ref bean="openSessionInViewInterceptor"/>
</list>
</property>
<property name="mappings">
....
</property>
</bean> ...
</beans>
OpenSessionInViewFilter配置:
<web-app>
<filter>
<filter-name>hibernateFilter</filter-name>
<filter-class> org.springframework.orm.hibernate3.support.OpenSessionInViewFilter </filter-class>
<!-- singleSession默认为true,若设为false则等于没用OpenSessionInView -->
<init-param>
<param-name>singleSession</param-name>
<param-value>true</param-value>
</init-param>
</filter> ...
<filter-mapping>
<filter-name>hibernateFilter</filter-name>
<url-pattern>*.do</url-pattern>
</filter-mapping>
...
</web-app>