servlet和JSP过滤器Filter

servlet和JSP过滤器Filter(20)       <filter-mapping>
        <filter-name>Reporter</filter-name>
        <url-pattern>/index.jsp</url-pattern>
      </filter-mapping>
      <!-- Also apply the Reporter filter to the servlet named
          "TodaysSpecial".
      -->
      <filter-mapping>
        <filter-name>Reporter</filter-name>
        <servlet-name>TodaysSpecial</servlet-name>
      </filter-mapping>
      <!-- ... -->
    
      <!-- Give a name to the Today's Special servlet so that filters
          can be applied to it.
      -->
      <servlet>
        <servlet-name>TodaysSpecial</servlet-name>
        <servlet-class>
          moreservlets.TodaysSpecialServlet
        </servlet-class>
      </servlet>
      <!-- ... -->
    
      <!-- Make /TodaysSpecial invoke the servlet
          named TodaysSpecial (i.e., moreservlets.TodaysSpecial).