struts2配置log4j

<interceptor-ref name="defaultStack"> 

     <param name="exception.logEnabled">true</param> 

     <param name="exception.logLevel">error</param> 

</interceptor-ref>

<package name="default" extends="struts-default">    <interceptor-stack name="defaultStack">       <interceptor-ref name="timer"/>    <interceptor-ref name="logger"/>        <interceptor-ref name="exception">             <param name="logEnabled">true</param>             <param name="logCategory">error.unhandled</param>             <param name="logLevel">WARN</param>       </interceptor-ref>    </interceptor-stack> </package>