这节课我们学了SSM框架增删改查。
新建文件：


User中的内容还是跟以前一样。

UserController中代码：
package com.zhongruan.controller;

import com.github.pagehelper.PageInfo;
import com.zhongruan.bean.User;
import com.zhongruan.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;

import java.util.List;

@Controller
public class UserController {
@Autowired
private IUserService userService;

@RequestMapping("/findAll.do")
public ModelAndView findAll(@RequestParam(defaultValue = "1") int pageNum, @RequestParam(defaultValue = "5") int size) {
    List<User> users=userService.findAll(pageNum,size);
    PageInfo<User> pageInfo=new PageInfo<>(users);
    ModelAndView modelAndView=new ModelAndView();
    modelAndView.setViewName("allUser.jsp");
    modelAndView.addObject("pageInfo",pageInfo);
    return modelAndView;

}
@RequestMapping("/login.do")
public String login(User user){
    Boolean flag=userService.login(user.getUsername(),user.getPassword());
    if(flag){
        return "redirect:/findAll.do";
    }else{
        return "failure.jsp";
    }
}
@RequestMapping("/delete.do")
public String deleteById(int id){
    userService.deleteById(id);
    return "redirect:/findAll.do";
}

@RequestMapping("/toUpdate.do")
public ModelAndView toUpdate(int id){
    User user=userService.selectById(id);
    ModelAndView mv=new ModelAndView();
    mv.addObject("user",user);
    mv.setViewName("updateUser.jsp");

    return mv;
}
@RequestMapping("/addUser.do")
public String addById(User user) {
    userService.addById(user);
    return "redirect:/findAll.do";
}


@RequestMapping("/toupdate.do")
public ModelAndView toupdate(User user) {
    int id = user.getId();
    User users = userService.findById(id);
   ModelAndView mv = new ModelAndView();
    mv.setViewName("updateUser.jsp");
    mv.addObject("users", users);
    return mv;
}
@RequestMapping("update.do")
public String update(User user){
    userService.update(user);
    return "redirect:/findAll.do";

}

}

IUserDao中代码：
package com.zhongruan.dao;

import com.zhongruan.bean.User;
import java.util.L