Springboot realizes simple login function through database

Simple login function through Springboot and MYSQL+Mybatis+thymeleaf

First create the Springboot project package

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Create a simple login user and password

configuration properties in mysql
First application.properties

This is a startup class generated by eclipse

Then write a User entity class in entity

package com.example.second.entity;

public class User {
    
    
	  private String username;
	    private String password;
		public String getUsername() {
    
    
			return username;
		}
		public void setUsername(String username) {
    
    
			this.username = username;
		}
		public String getPassword() {
    
    
			return password;
		}
		public void setPassword(String password) {
    
    
			this.password = password;
		}
	    
}

Then to the data access layer (Dao)

package com.example.second.dao;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Component;

import com.example.second.entity.User;

@Mapper
@Component(value="userDao")
public interface UserDao {
    
    
	//登录功能接口
	public User Login(@Param("username")String username,
	   @Param("password")String password);

}

Then create an .xml file in the mapper package
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and then go to the data service layer (Service)

package com.example.second.service.impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.example.second.dao.UserDao;
import com.example.second.entity.User;
import com.example.second.service.UserService;

@Service("UserService")
public class UserServiceImpl implements UserService{
    
    
	@Autowired
	private UserDao userDao;
	@Override
	public User Login(String username, String password) {
    
    
		return userDao.Login(username, password);
	}
}

And Service interface

package com.example.second.service;

import com.example.second.entity.User;

public interface UserService {
    
    
 public User Login(String username,String password);
}

Finally to the front controller (Controller)

package com.example.second.controller;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.servlet.ModelAndView;

import com.example.second.entity.User;
import com.example.second.service.UserService;
@Controller
public class UserController {
    
    
	@Autowired
	private UserService userService;
	@PostMapping(value="/logining")
	public ModelAndView login(HttpServletRequest request,ModelAndView mv, User u) {
    
    
		String username=request.getParameter("username");
		String password=request.getParameter("password");
		u=userService.Login(username, password);
		if(u!=null) {
    
    
			mv.setViewName("logining");
			mv.addObject("info", "登陆成功");
			return mv;
		}
		mv.setViewName("logining");
		mv.addObject("info", "登陆失败");
		return mv;
		
	}
	
}

Also write a login page login.html controller

package com.example.second.controller;

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

//登录页面控制
@Controller
public class PageController {
    
    
	@RequestMapping(value="/login")
	public String str(String s) {
    
    
		return "logining";
	}
}

Because we use @Controller (I will do an explanation next time) and
finally write a login.html to implement front-end login

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>实现简单的登录</title>
</head>
<body> 
<center>
<table>
	<form action="/logining" method="post">
	<tr>
	<td>
	  <input type="text" name="username">
	  </td>
	   </tr>
	  <tr>
	  <td>
	  <input type="password"  name="password">
	    </td>
	  </tr>
	  <tr>
	  <td>
	  <input  type="submit" value="登陆" >
	     </td>
	  </tr>
	</form>
		<span th:text="${info}"></span>
</table>
</center>
</body>
</html>

Run the screenshot to
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log in successfully.

Note: If you are not using the mysql user and password, you will be prompted that the login failed!