SpringBoot登录页面

entity层

 int id;
    String username;
    String password;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    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;
    }

mapper层

 User findByUsername(String username);

    User getByUsernameAndPassword(String username,String password);

controller层

@Controller
public class LoginController {

    @Resource
    UserService userService;

@RequestMapping("/login")
	public String Login() {
		return "Login";
	}

service层

public interface UserService {
//注册
 public void addUser(User user) ;
 //登录
 public User SelectUserByName(String username,String password);
 
}

application.properties文件

spring.datasource.url=jdbc:mysql://localhost:3306/user?characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

注意事项：代码只写了主要部分，旨在帮助大家更好的理解代码，达到能够独立书写代码，谢谢大家！