使用Tomcat10时，建类 public class ViewBaseServlet extends HttpServlet，出现：private TemplateEngine templateEngine;报Cannot resolve symbol 'TemplateEngine'错误

目前已使用的办法：找到Tomcat的lib，sevlet-api.jar 并且已经添加，但是仍然不行。
在创建
public class ViewBaseServlet extends HttpServlet

时报如下错误
如
private TemplateEngine templateEngine;
会报
Cannot resolve symbol ‘TemplateEngine’错误
如
//1. 获取当前Servlet的ServletContext对象
ServletContext servletContext = this.getServletContext();
//2. 创建Thymeleaf解析器对象,其接收:一个ServletContext对象
ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver(servletContext);
会报
Cannot resolve symbol ‘ServletContextTemplateResolver’
等等类似