我的interceptor为何不起作用？(xwork.xml内容显示出来了)

<xwork>
   <include file="webwork-default.xml"/>
   
   <package name="default" extends="webwork-default">
     <!-- Include webwork defaults (from WebWork JAR). -->
     <default-interceptor-ref name="completeStack"/>

      <action name="helloWorld"
                class="test.HelloWorldAction">
         <result name="success">hello.jsp</result>
         <result name="input">name.jsp</result>
      </action>
   </package>
  </xwork>
<p class="indent">