web.xml 配置servlet

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
  version="3.1"
  metadata-complete="true">
        <display-name>Private Blog Of mtl6906</display-name>
        <description>
                no thing...
        </decription>
<!--
        <servlet>
                <servlet-name></servlet-name>
                <servlet-class></servlet-class>
        </servlet>
        <servlet-mapping>
                <servlet-name></servlet-name>
                <url-pattern></pattern>
        </servlet-mapping>
-->

        <servlet>
                <servlet-name>index</servlet-name>
                <servlet-class>Index</servlet-class>
        </servlet>
        <servlet-mapping>
                <servlet-name>index</servlet-name>
                <url-pattern>/index.do</pattern>
        </servlet-mapping>
</web-app>