生手，web项目中，web.xml里面的东西搞不懂啊

新手，web项目中，web.xml里面的东西搞不懂啊，
谁能给解释下啊

	<filter-mapping>
		<filter-name>hibernateFilter</filter-name>
		<url-pattern>*.do</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>hibernateFilter</filter-name>
		<url-pattern>*.dwr</url-pattern>
	</filter-mapping>
	<!-- 让hibernate open session in view的荣光也照耀xfire -->
	<filter-mapping>
		<filter-name>hibernateFilter</filter-name>
		<url-pattern>/service/*</url-pattern>
	</filter-mapping>
	<!-- 页面元素的GZIP压缩 Filter，减少网络带宽 -->
	<filter-mapping>
		<filter-name>compressFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	
		<filter>
		<filter-name>shiroFilter</filter-name>
		<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
			<init-param>
    			<param-name>targetFilterLifecycle</param-name>
     			<param-value>true</param-value>
   			</init-param>
	</filter>
	<filter-mapping>
		<filter-name>shiroFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping> 
	
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>*.do</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>*.jsp</url-pattern>
		<dispatcher>REQUEST</dispatcher>
        <dispatcher>FORWARD</dispatcher>
        <dispatcher>INCLUDE</dispatcher>
	</filter-mapping>
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>/struts/*</url-pattern>
	</filter-mapping>

	<filter-mapping>
		<filter-name>SessionFilter</filter-name>
		<url-pattern>*.do</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>SessionFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>SessionFilter</filter-name>
		<url-pattern>/*Servlet</url-pattern>
	</filter-mapping>

------解决思路----------------------
当你request的请求参数类型满足filter-mappiing下的url-pattern的值时就会被过滤，你只截了一半吧，还有每个过滤器对应配置的类，满足条件的话，就会进入过滤器的类里面进行处理