servlet创建后还需要在web.xml中进行配置,比如<url-pattern>
具体格式如下:
<web-app>
  <servlet>
    <servlet-name>controller</servlet-name>
    <servlet-class>mvc.Controller</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>controller</servlet-name>
    <url-pattern>/controller</url-pattern>
  </servlet-mapping>
</web-app>
<url-pattern>/controller</url-pattern>表示,当你在地址栏里输入的url以/controller为结尾时,才调用你的servlet