Tomcat总是运行失败

Question

我想在Tomcat中构建一个Web项目，但代码总是无法运行。 我尝试了网上的很多提示，但没有成功。 因为我是Java初学者，所以我提供我的IDEA设置。

public class AddServlet extends HttpServlet {
    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String fname = request.getParameter("fname");
        String priceStr = request.getParameter("price");
        Integer price = Integer.parseInt(priceStr);
        String fcountStr = request.getParameter("fcount");
        Integer fcount = Integer.parseInt(fcountStr);
        String remark = request.getParameter("remark");

        System.out.println("fname = " +fname);
        System.out.println("price = " +price);
        System.out.println("fcount = " +fcount);
        System.out.println("remark = " +remark);
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <servlet>
        <servlet-name>AddServlet</servlet-name>
        <servlet-class>com.atguigu.servlets.AddServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>AddServlet</servlet-name>
        <url-pattern>/add</url-pattern>
    </servlet-mapping>

https://i.sstatic.net/0RaWZ.jpg