Idea报错Cannot resolve symbol 'HttpServlet'

Idea Import Project Can not resolve symbol 'HttpServlet' error:

import eclipse projects such error Reference: https://blog.csdn.net/lihua5419/article/details/94742369

1、File->Settings->Application Servers->+ Tomcat Server->选择tomcat->OK

2, right-project selection Open Module Setting->

Select Global Libraries -> + -> Java- >

Just set the directory into the Tomcat servlet-api.jar selected under lib,