代码太多就不逐一展示了，到目前为止这几个类之间的关系还是有点不太清楚。
package controller; import bean.User; import dao.UserDao; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.ModelAndView; import service.IUserService; import java.util.List; @Controller @RequestMapping("/user") public class UserController { @Autowired private IUserService userService; @Autowired private UserDao userDao; @RequestMapping("/login.do") public ModelAndView login(User user){ boolean flag=userService.login(user.getUsername(),user.getPassword()); ModelAndView modelAndView=new ModelAndView(); if (flag){ // List userList=userDao.findAllUser(); // modelAndView.addObject("userlist",userList); modelAndView.setViewName("main"); }else { modelAndView.setViewName("failer"); } return modelAndView; } @RequestMapping("/findAllUser.do") public ModelAndView findAllUser(){ ModelAndView modelAndView=new ModelAndView(); List userList=userDao.findAllUser(); modelAndView.addObject("userlist",userList); modelAndView.setViewName("user-list"); return modelAndView; } @RequestMapping("/deleteById.do") public String delete(int id){ userService.deleteById(id); return "redirect:findAllUser.do"; } @RequestMapping("/toUpdate.do") public ModelAndView toUpdate(int id){ User user=userService.selectUserBydId(id); ModelAndView modelAndView=new ModelAndView(); modelAndView.setViewName("user-update"); modelAndView.addObject("user",user); return modelAndView; } @RequestMapping("/Update.do") public String Update(User user){ userService.update(user); return "redirect:findAllUser.do"; } } package service.impl; import bean.User; import dao.UserDao; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import service.IUserService; import java.util.List; @Service public class UserService implements IUserService { @Autowired private UserDao userDao; @Override public boolean login(String username, String password) { User user=userDao.findUserByUsername(username); if (user!=null&&user.getPassword().equals(password)){ return true; } return false; } @Override public List<User> findAllUser(){ return userDao.findAllUser(); } @Override public void deleteById(int id){ userDao.deleteById(id); } @Override public void add(User user) { userDao.add(user); } @Override public User selectUserBydId(int id) { return userDao.selectById(id); } @Override public void update(User user){ userDao.update(user); } } package dao; import bean.User; import java.util.List; public interface UserDao { User findUserByUsername(String username); List<User> findAllUser(); void deleteById(int id); void add(User user); User selectById(int id); void update(User user); } <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="dao.UserDao" > <select id="findUserByUsername" parameterType="String" resultType="user"> select * from User where username=#{username} </select> <select id="findAllUser" resultType="user"> select * from User </select> <delete id="deleteById" parameterType="int" > delete from User where id=#{id} </delete> <insert id="add" parameterType="user" > insert into User (username,password) values (#{username},#{password}) </insert> <select id="selectById" parameterType="int" resultType="user"> select * from User where id=#{id} </select> <update id="update" parameterType="user"> update User set username=#{username},password=#{password} where id=#{id} </update> </mapper>