例如下面的配置,如何在代码里获取已经配置的两个FILTER?<filter>    
     <filter-name>filter1</filter-name>    
     <filter-class>com.web.filter1</filter-class>    
</filter>    
<filter-mapping>    
     <filter-name>filter1</filter-name>    
     <url-pattern>*.do</url-pattern>    
</filter-mapping> <filter>    
     <filter-name>filter2</filter-name>    
      <filter-class>com.web.filter2</filter-class>    
</filter>    
<filter-mapping>    
     <filter-name>filter2</filter-name>    
      <url-pattern>*.do</url-pattern>    
</filter-mapping>