老师，我不知道到底哪里有问题这个

用test就可以显示出来

add就报404

package com.imooc.controller;

import com.imooc.dao.TeacherDao;
import com.imooc.entity.Teacher;
import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;


@Controller
public class TeacherController {
   @Autowired
   private TeacherDao teacherDao;

   @RequestMapping("/test")
   @ResponseBody
   public String test(int id) {
       return "id:" + id;
   }

   @PostMapping(value = "/add")
   public String add(Teacher teacher) {
       teacherDao.add(teacher);
       return "redirect:/selectAll";
   }

   @GetMapping(value = "/selectById/{id}")
   public ModelAndView selectById(@PathVariable(value = "id") int id) {
       Teacher teacher = teacherDao.selectById(id);
       ModelAndView modelAndView = new ModelAndView();
       modelAndView.addObject("teacher", teacher);
       modelAndView.setViewName("update");
       return modelAndView;
   }

   @PutMapping(value = "/update")
   public String update(Teacher teacher) {
       teacherDao.update(teacher);
       return "redirect:/selectAll";
   }

   @DeleteMapping(value = "/delete/{id}")
   public String delete(@PathVariable(value = "id")int id){
       teacherDao.delete(id);
       return "redirect:/selectAll";
   }


   @GetMapping("/selectAll")
   public ModelAndView selectAll(){
       ModelAndView modelAndView = new ModelAndView();
       modelAndView.addObject("teachers",teacherDao.selectAll());
       modelAndView.setViewName("index");
       return modelAndView;
}
}

<?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"
      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">


   <!-- 配置自动扫描 -->
   <context:component-scan base-package="com.imooc"></context:component-scan>

   <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
       <property name="prefix" value="/"></property>
       <property name="suffix" value=".jsp"></property>
   </bean>
</beans>

报的错误

org.springframework.web.servlet.PageNotFound.noHandlerFound No mapping found for HTTP request with URI [/SpringMVCRestful_war_exploded/add] in DispatcherServlet with name 'springmvc'

请老师帮我解决这个问题