struts上传文件限制大小

<action name="fileupload" class="Action.FileUploadAction" method="uploadFile">
<result name="success">
/upload_success.jsp
</result>
<result name="error">
/upload_error.jsp
</result>
<result name="input">/fileUpload.jsp</result>
<interceptor-ref name="fileUpload">
<param name="maximumSize">20971520</param>

</interceptor-ref>
<interceptor-ref name="defaultStack"></interceptor-ref>

</action>