struts.xml加载失败的问题

Caused by: Unable to load file:/D:/eclipse-jee-mars-1-win32/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp1/wtpwebapps/dynamicDBsource/WEB-INF/classes/struts.xml - [unknown location]

知道是struts.xml加载失败的问题

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="true" />
    <constant name="struts.devMode" value="true" />

    <package name="default" namespace="/" extends="struts-default">
    
       <action name="student_*" class="com.xh.dataSource.action.StuAction" method="{1}">
       		<result name="addUI">/WEB-INF/view/addUI.jsp</result>
   			<result name="list">/WEB-INF/view/list.jsp</result>
   			<result name="add">/WEB-INF/view/list.jsp</result>
       		
   
       </action>
       
      
    </package>

</struts>

可是检查N遍都没发现问题。

对比以前的项目，发现：

 "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"