web.xml分发器：

　　case1: springMvc的分发器：

　　　　作用：将匹配上的请求交由springMvc处理，路径会继续到达springMvc的处理器映射器

    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring/*-servlet.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

　　case2: 自定义servlet分发器：

　　　　　作用：在自己的servlet中可以自由处理，web.xml的url优先匹配已定义的pattern，最后匹配<url-pattern>/</url-pattern>

  <servlet>
      <servlet-name>Func1</servlet-name>
      <servlet-class>com.softroad.fun1.action.Func1_Servlet</servlet-class>
  </servlet>
  
  <servlet-mapping>
      <servlet-name>Func1</servlet-name>
      <url-pattern>/Func1/*</url-pattern>
  </servlet-mapping>

web.xml过滤器：

　　自定义过滤器：拦截请求、验证权限、文件加密或者解密

  <filter>
      <filter-name>Filter1</filter-name>
      <filter-class>com.softroad.filter.Login_Filter</filter-class>
  </filter>
  
  <filter-mapping>
      <filter-name>Filter1</filter-name>
      <url-pattern>/Func2/*</url-pattern>
  </filter-mapping>