1. <?xml version="1.0" encoding="UTF-8"?>
    2. <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    4.          xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
    5.          version="4.0">
    7.   <servlet>
    8.     <servlet-name>HelloWorld</servlet-name>
    9.     <servlet-class>com.itbaizhan.servlet.HelloWorld</servlet-class>
    10.   </servlet>
    12.   <servlet-mapping>
    13.     <servlet-name>HelloWorld</servlet-name>
    14.     <url-pattern>/helloworld.do</url-pattern>
    15.   </servlet-mapping>
    16. </web-app>