如何配置struts2拦截器

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> --> <? xml version="1.0" encoding="UTF-8"  ?>
<! DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd" >
< struts >
     < constant  name ="struts.devMode"  value ="true"   />
     < constant  name ="struts.i18n.reload"  value ="true"   />
     < constant  name ="struts.configuration.xml.reload"  value ="true"   />
     < constant  name ="struts.i18n.encoding"  value ="gb2312"   />
     < constant  name ="struts.custom.i18n.resources"
        value ="messageResource"   />
     < constant  name ="struts.action.extension"  value ="jspa"   />
     < constant  name ="struts.multipart.saveDir"  value ="/tmp"   />
     < constant  name ="struts.multipart.maxSize"  value ="10000000"   />
     < constant  name ="struts.ui.theme"  value ="simple"   />
     < package  name ="default"  extends ="struts-default" >
         < interceptors >
             < interceptor  name ="exceptionInterceptor"
                class ="org.roadway.wisp.zd.util.ExceptionInterceptor" >
                 < param  name ="interceptorName" >
                    self-interceptor
                 </ param >
             </ interceptor >
             < interceptor-stack  name ="myStack" >
                 < interceptor-ref  name ="defaultStack"   />
                 < interceptor-ref  name ="exceptionInterceptor"   />
             </ interceptor-stack >
         </ interceptors >
         < default-interceptor-ref  name ="myStack"   />
         < global-exception-mappings >
             < exception-mapping  result ="error"
                exception ="java.lang.Exception"   />
         </ global-exception-mappings >
     </ package >
     < include  file ="register.xml"   />
</ struts >