解决hibernate 设置为lazy=“true”的集合，通过struts1 访问的时候报session已经关闭的问题

在使用struts1 + hibernate（Struts2没有这问题）过程中，经常要访问lazy="true"的集合类型属性，可是这时候报session已经关闭的现象。

要解决这个问题我们要分析OpenSessionInViewFilter这个类。 OpenSessionInViewFilter是按照WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE这个key去获取spring配置信息的！ 所以，我们在使用过程中配置OpenSessionInViewFilter就不起作用。

解决方法： 修改ContextLoaderPlugIn代码，在getServletContext().setAttribute(attrName, wac);这个地方加上一行代码：  getServletContext().setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, wac);  
 或者

修改OpenSessionInViewFilter，让它按照attrName去取得spring配置。 

我们按照第一种方法来配置

1.重写struts的插件继承自spring的ContextLoaderPlugIn 的类。

package com.test.plugIn;

import org.springframework.beans.BeansException;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springframework.web.struts.ContextLoaderPlugIn;


public class MyContextLoaderPlugIn extends ContextLoaderPlugIn {
	protected WebApplicationContext initWebApplicationContext()
			throws BeansException, IllegalStateException {
		WebApplicationContext parent = WebApplicationContextUtils
				.getWebApplicationContext(getServletContext());

		WebApplicationContext wac = createWebApplicationContext(parent);

		String attrName = getServletContextAttributeName();
		getServletContext().setAttribute(attrName, wac);
		getServletContext().setAttribute(
				WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE,
				wac); 
		return wac;
	}

}

 2.配置web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	version="2.5"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

	<filter>
		<filter-name>Set Character Encoding</filter-name>
		<filter-class>
			com.navinfo.telematics.roadmap.web.filter.SetCharacterEncodingFilter</filter-class>
		<init-param>
			<param-name>encoding</param-name>
			<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter>
    <filter-name>hibernateFilter</filter-name>
        <filter-class>
           org.springframework.orm.hibernate3.support.OpenSessionInViewFilter
         </filter-class>
    </filter>
	<filter-mapping>
	   <filter-name>hibernateFilter</filter-name>
	    <url-pattern>*.do</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>Set Character Encoding</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	<servlet>
		<servlet-name>action</servlet-name>
		<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
		<init-param>
			<param-name>config</param-name>
			<param-value>/WEB-INF/struts-config.xml</param-value>
		</init-param>
		<init-param>
			<param-name>debug</param-name>
			<param-value>3</param-value>
		</init-param>
		<init-param>
			<param-name>detail</param-name>
			<param-value>3</param-value>
		</init-param>
		<load-on-startup>0</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>action</servlet-name>
		<url-pattern>*.do</url-pattern>
	</servlet-mapping>

	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
</web-app>

 3.更改struts-config.xml 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN" "http://struts.apache.org/dtds/struts-config_1_3.dtd">

<struts-config>
	<form-beans>
	........	
	</form-beans>
	<global-exceptions />
	<global-forwards />
	<action-mappings>
  	.......
	</action-mappings>
	<message-resources parameter="i18n.ApplicationResources" />
	<plug-in
		className="com.test.plugIn.MyContextLoaderPlugIn">
		<set-property property="contextConfigLocation"
			value="/WEB-INF/classes/spring/applicationContext.xml" />
	</plug-in>
</struts-config>