struts2_项目运行报404

1.缺少jar包,commons-lang3-3.2.jar

参考网址:https://blog.csdn.net/u013457382/article/details/50972401

2.struts.xml配置错误

 <struts>
     <package name="struts2" extends="struts-default" namespace="">
         <action name="userModel" class="com.ahd.action.UserModelAction">
             <result>/success.jsp</result>
         </action>
     </package>
 </struts>

阴影部分为长出错地方

3.web.xml文件配置错误(少见)

 <filter>
         <filter-name>struts2</filter-name>
         <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
     </filter>
     <filter-mapping>
         <filter-name>struts2</filter-name>
         <url-pattern>/*</url-pattern>
     </filter-mapping>