@RequestMapping("/register")
    public void register(){
        //  写入数据
        User user = new User();
        user.setUserName("wg??");
        user.setUserPassword("123457888");
        userMapper.insert(user);
        System.out.println(user.getUserName() + " " + user.getUserPassword() );
    }

    @RequestMapping("/delete")
    public String delete(){
        //  通过主键来删除数据
//        userMapper.deleteByPrimaryKey((long)1);
        UserExample userExample = new UserExample();
        userExample.createCriteria().andUserPasswordEqualTo("wg?");
        userMapper.deleteByExample(userExample);
        return "success";
    }

    @RequestMapping("/select")
    public String select(){
        //  查询数据
        UserExample userExample = new UserExample();
        userExample.createCriteria().andUserPasswordEqualTo("12345788");
        List<User> userList = userMapper.selectByExample(userExample);

        System.out.println(userList.size()+"?");

        if(userList.size()==1){
            System.out.println("登录成功");
        }else{
            System.out.println("登录失败");
        }
        return "success";
    }

    @RequestMapping("/updata")
    public String updata(){
        //  修改数据
        User user = new User();

        user.setId(1L);
        user.setUserName("增幅");
        user.setUserPassword("19999");

        userMapper.updateByPrimaryKeySelective(user);

        return "success";
    }