依赖网址:https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api/3.1.0
https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api/2.3.1
https://mvnrepository.com/artifact/org.springframework/spring-webmvc
创建文件夹
修改版本号
配置好依赖要刷新
如果不刷新,spring就不出来
