怎么获取WEB.XML中配置的FILTER信息？
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>
