已经上线的项目报错问题！：报错

Stack-trace
There is no Action mapped for namespace /web and action name getArticleListByType. - [unknown location]
      at com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:177)
      at org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
      at org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
      at com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
      at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:458)
      at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
      at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
      at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:568)
      at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
      at org.apache.coyote.http11.Http11NioProcessor.process(Http11NioProcessor.java:880)
      at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:719)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:2081)
      at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)

这个问题到底是怎么回事？这个action名称，我的struts.xml中根本没有啊，真不知道什么原因了，

以下是部分struts.xml的配置文件。

<constant name="struts.action.extension" value="action,shtml"/>
 <package name="web" extends="struts-default">
  <global-results>
   <result name="error">/web/error.jsp</result>
  </global-results>
 </package>