SpringMVC项目中web.xml中的节点加载顺序问题，之前以为web.xml中就是一些配置信息，和节点的顺序没有关系，后来才发现初始化时的加载顺序是和节点的顺序相关的。

完整的web.xml文件内容：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
		<!--
		Spring ApplicationContext配置文件的路径,可使用通配符，多个路径用,号分隔
		此参数用于后面的Spring-Context loader
	-->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath*:/spring/*.xml</param-value>
	</context-param>
	
	<filter>
		<filter-name>encodingFilter</filter-name>
		<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
		<init-param>
			<param-name>encoding</param-name>
			<param-value>UTF-8</param-value>
		</init-param>
		<init-param>
			<param-name>forceEncoding</param-name>
			<param-value>true</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>encodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>authenticationFilter</filter-name>
		<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
	</filter>
	
	<filter-mapping>
         <filter-name>authenticationFilter</filter-name>
         <url-pattern>/*</url-pattern>
    </filter-mapping>
         
    <filter>
		<filter-name>authorizationFilter</filter-name>
		<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
	</filter>
	
	<filter-mapping>
         <filter-name>authorizationFilter</filter-name>
         <url-pattern>/*</url-pattern>
    </filter-mapping>

	<listener>
        <listener-class>com.auth.spring.listener.SpringLoaderListener</listener-class>
    </listener>
    
  	 <listener>
        <listener-class>com.abc.mobile.web.MobileLoader</listener-class>
    </listener>
   
    <listener>  
         <listener-class>  
            com.auth.listener.HttpSessionManager  
        </listener-class>  
    </listener>  
   
	<!-- 防止spring内存溢出监听器 -->
	<listener>
		<listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
	</listener>
	
	<listener>
    	<listener-class>com.abc.conference.context.RpcManager</listener-class>
  	</listener>
  	<servlet>
		<servlet-name>Action</servlet-name>
		<servlet-class>com.abc.conference.apis.Action</servlet-class>
	</servlet>
	
	 <servlet>    
        <servlet-name>t1</servlet-name>    
        <servlet-class>com.abc.base.web.init.BaseDataServlet</servlet-class>    
       <!-- 如果需要自动加载，加下面一句 -->    
       <load-on-startup>1</load-on-startup>    
    </servlet>
	
	<servlet-mapping>
		<servlet-name>Action</servlet-name>
		<url-pattern>/public/Action</url-pattern>
	</servlet-mapping>
	
	<servlet>
        <servlet-name>middleware</servlet-name>
        <servlet-class>com.abc.mobile.web.ActionProxy</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>middleware</servlet-name>
        <url-pattern>/public/middleware</url-pattern>
    </servlet-mapping>


	<!-- spring mvc servlet -->
<!-- springmvc 配置 -->
	<servlet>
		<servlet-name>springmvc</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		 <init-param>  
            <param-name>contextConfigLocation</param-name>  
            <param-value>classpath*:/springmvc-servlet.xml</param-value>  
        </init-param>  
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>springmvc</servlet-name>
		<url-pattern>*.do</url-pattern>  
	</servlet-mapping>
	
	<servlet>
		<description></description>
		<display-name>ServletLoader</display-name>
		<servlet-name>ServletLoader</servlet-name>
		<servlet-class>com.abc.conference.context.ServletLoader</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	
	<servlet>
		<display-name>middlewareInit</display-name>
		<servlet-name>middlewareInit</servlet-name>
		<servlet-class>com.abc.middleware.init.MiddlewareServletLoader</servlet-class>
		<load-on-startup>2</load-on-startup>
	</servlet>
	
	<welcome-file-list>
		<welcome-file>/index.jsp</welcome-file>
	</welcome-file-list>
	<!-- 配置session超时时间，单位分钟 -->
	<session-config>
		<session-timeout>15</session-timeout>
	</session-config>
</web-app>

因为在Action中用到了一些静态变量，而这个静态变量是在BaseDataServlet中初始化的，所以如果

	 <servlet>    
        <servlet-name>t1</servlet-name>    
        <servlet-class>com.abc.base.web.init.BaseDataServlet</servlet-class>    
       <!-- 如果需要自动加载，加下面一句 -->    
       <load-on-startup>1</load-on-startup>    
    </servlet>

配置节点，在Action：

	<servlet-mapping>
		<servlet-name>Action</servlet-name>
		<url-pattern>/public/Action</url-pattern>
	</servlet-mapping>

节点之后的话，那调用静态变量的时候，静态变量的值就是Null，因为这时还没有初始化呢。