openinview

我原来用struts/spring/hibernate的时候同样使用OpenSessionInView，但是似乎没有robbin所说的问题啊。而且我在使用的时候，是ContextLoaderListener和ContextLoaderPlugIn一起用的。整个配置如下：
1.首先是web.xml

<filter>
       <filter-name>OpenSessionInViewFilter</filter-name>
       <filter-class>org.springframework.orm.hibernate.support.OpenSessionInViewFilter</filter-class>
   </filter>

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

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

.....

	<filter>
        <filter-name>OpenSessionInViewFilter</filter-name>
        <filter-class>org.springframework.orm.hibernate.support.OpenSessionInViewFilter</filter-class>
    </filter>
    
    <filter-mapping>
        <filter-name>OpenSessionInViewFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    
    <listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

......

2. 然后是struts-config.xml：

<plug-in className="org.springframework.web.struts.ContextLoaderPlugIn">
    <set-property property="contextConfigLocation"
                  value="/WEB-INF/action-servlet.xml"
    />
</plug-in>

<plug-in className="org.springframework.web.struts.ContextLoaderPlugIn">
	<set-property property="contextConfigLocation" 
				  value="/WEB-INF/action-servlet.xml" 
	/>
</plug-in>

其余部分省略。

在上述配置下，使用OpenSessionInView似乎没有问题。

不知道robbin所说的ContextLoaderListener和ContextLoaderPlugIn不应该同时使用是不是做得是如下的配置：（struts-config.xml）

<plug-in
className="org.springframework.web.struts.ContextLoaderPlugIn">
<set-property property="contextConfigLocation"
value="/WEB-INF/applicationContext.xml,
/WEB-INF/action-servlet.xml"/>
</plug-in>

<plug-in
className="org.springframework.web.struts.ContextLoaderPlugIn">
<set-property property="contextConfigLocation"
value="/WEB-INF/applicationContext.xml,
/WEB-INF/action-servlet.xml"/>
</plug-in>

我尝试了一下，用这种配置时，OpenSessionInView的确失效了。

我猜想，原因大概是这样：struts的这个plugIn，可能只是为了整合一个action-servlet.xml，将action-servlet.xml中的定义当作Spring的bean来使用，因此，在保存时，只要有action-servlet.xml的配置，就被保存到robbin所提到的那个attrName中，而不是WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE中，所以，OpenSessionInView是取不到这个配置的。

那么这个配置什么时候被取到呢？直觉告诉我，可能是和Action的Proxy有关。于是，查看了org.springframework.web.struts.DelegatingActionProxy的源码，果然：

/**
     * Return the delegate Action for the given mapping.
     * <p>The default implementation determines a bean name from the
     * given ActionMapping and looks up the corresponding bean in the
     * WebApplicationContext.
     * @param mapping the Struts ActionMapping
     * @return the delegate Action
     * @throws BeansException if thrown by WebApplicationContext methods
     * @see #determineActionBeanName
     */
    protected Action getDelegateAction(ActionMapping mapping); throws BeansException {
        WebApplicationContext wac = getWebApplicationContext(getServlet();, mapping.getModuleConfig(););;
        String beanName = determineActionBeanName(mapping);;
        return (Action); wac.getBean(beanName, Action.class);;
    }

    /**
     * Fetch ContextLoaderPlugIn's WebApplicationContext from the
     * ServletContext, containing the Struts Action beans to delegate to.
     * @param actionServlet the associated ActionServlet
     * @param moduleConfig the associated ModuleConfig
     * @return the WebApplicationContext
     * @throws IllegalStateException if no WebApplicationContext could be found
     * @see DelegatingActionUtils#getRequiredWebApplicationContext
     * @see ContextLoaderPlugIn#SERVLET_CONTEXT_PREFIX
     */
    protected WebApplicationContext getWebApplicationContext(
            ActionServlet actionServlet, ModuleConfig moduleConfig); throws IllegalStateException {
        return DelegatingActionUtils.getRequiredWebApplicationContext(actionServlet, moduleConfig);;
    }

/**
	 * Return the delegate Action for the given mapping.
	 * <p>The default implementation determines a bean name from the
	 * given ActionMapping and looks up the corresponding bean in the
	 * WebApplicationContext.
	 * @param mapping the Struts ActionMapping
	 * @return the delegate Action
	 * @throws BeansException if thrown by WebApplicationContext methods
	 * @see #determineActionBeanName
	 */
	protected Action getDelegateAction(ActionMapping mapping); throws BeansException {
		WebApplicationContext wac = getWebApplicationContext(getServlet();, mapping.getModuleConfig(););;
		String beanName = determineActionBeanName(mapping);;
		return (Action); wac.getBean(beanName, Action.class);;
	}

	/**
	 * Fetch ContextLoaderPlugIn's WebApplicationContext from the
	 * ServletContext, containing the Struts Action beans to delegate to.
	 * @param actionServlet the associated ActionServlet
	 * @param moduleConfig the associated ModuleConfig
	 * @return the WebApplicationContext
	 * @throws IllegalStateException if no WebApplicationContext could be found
	 * @see DelegatingActionUtils#getRequiredWebApplicationContext
	 * @see ContextLoaderPlugIn#SERVLET_CONTEXT_PREFIX
	 */
	protected WebApplicationContext getWebApplicationContext(
			ActionServlet actionServlet, ModuleConfig moduleConfig); throws IllegalStateException {
		return DelegatingActionUtils.getRequiredWebApplicationContext(actionServlet, moduleConfig);;
	}

仔细看其中的取wac的代码，它并不是从WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE取的wac。

由此，我相信，除了robbin讲的修改源码以外，同时使用ContextLoaderListener和ContextLoaderPlugIn，但是不要在ContextLoaderPlugIn里面加入applicationContext.xml，只要加入你的action-servlet.xml，我相信，同样也可以非常流畅的使用OpenSessionInView