Tomcat 404 Http Not Found

我正在學習Spring MVC，並構建了第一個「hello world」示例。但我無法訪問該頁面。它說：「原始服務器沒有找到目標資源的當前表示，或者不願意透露目標資源存在。」我正在使用Tocat 9.0（我也嘗試過Tomcat 8仍然不能正常工作）。因此，這裏是我的下面Tomcat 404 Http Not Found

控制器代碼：

package com.emin.springdemo.mvc; 

import org.springframework.stereotype.Controller; 
import org.springframework.web.bind.annotation.RequestMapping; 

@Controller 
public class HomeController { 

    @RequestMapping("/") 
    public String showPage() { 

     return "main-menu"; 
    } 
}

JSP文件：

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" 
    pageEncoding="ISO-8859-1"%> 
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> 
<title>Insert title here</title> 
</head> 
<body> 
    <h2>Spring MVC Demo</h2> 
</body> 
</html>

servlet.xml中：

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:context="http://www.springframework.org/schema/context" 
    xmlns:mvc="http://www.springframework.org/schema/mvc" 
    xsi:schemaLocation=" 
     http://www.springframework.org/schema/beans 
     http://www.springframework.org/schema/beans/spring-beans.xsd 
     http://www.springframework.org/schema/context 
     http://www.springframework.org/schema/context/spring-context.xsd 
     http://www.springframework.org/schema/mvc 
     http://www.springframework.org/schema/mvc/spring-mvc.xsd"> 

    <!-- Step 3: Add support for component scanning --> 
    <context:component-scan base-package="com.emin.springdemo.mvc" /> 

    <!-- Step 4: Add support for conversion, formatting and validation support --> 
    <mvc:annotation-driven/> 

    <!-- Step 5: Define Spring MVC view resolver --> 
    <bean 
     class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 
     <property name="prefix" value="/WEB-INF/view/" /> 
     <property name="suffix" value=".jsp" /> 
    </bean> 

</beans>

的web.xml：