Step-by-Step Guide to Building a Spring Boot Application with MyBatis and MySQL

First, create a Spring Boot project using Spring Initializr, selecting the dependencies Spring Web, Thymeleaf, JDBC API, Spring Data JDBC, and MySQL Driver.

Next, add the required Maven dependencies in pom.xml :

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>springboot-web04</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.3</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.1</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

Configure the data source in application.yml (or application.properties ) to point to a MySQL database named mybatis :

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT%2B8&useSSL=true
    username: root  # database user
    password: sm1208  # password

# application.properties example
server.port=8080
spring.thymeleaf.cache=false
mybatis.mapper-locations=classpath:mapper/*.xml
type=com.alibaba.druid.pool.DruidDataSource

Create a simple POJO to hold login data:

package springbootweb04.demo.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class UserLogin {
    private String username;
    private String password;
}

Set up a MySQL database mybatis and a table userLogin with columns username and password . Connect to the database from IntelliJ IDEA via the Data Source view.

Define a MyBatis mapper interface and its XML mapping file:

package springbootweb04.demo.mapper;

import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import springbootweb04.demo.pojo.UserLogin;
import java.util.List;

@Mapper
@Repository
public interface UserLoginMapper {
    List
queryAll();
    int add(UserLogin userLogin);
    UserLogin queryByName(String username);
}

<?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="springbootweb04.demo.mapper.UserLoginMapper">
    <select id="queryAll" resultType="springbootweb04.demo.pojo.UserLogin">
        SELECT * FROM userLogin
    </select>
    <insert id="add" parameterType="springbootweb04.demo.pojo.UserLogin">
        INSERT INTO userLogin VALUES (#{username}, #{password})
    </insert>
    <select id="queryByName" resultType="springbootweb04.demo.pojo.UserLogin">
        SELECT * FROM userLogin WHERE username = #{username}
    </select>
</mapper>

Write a simple test to verify the datasource and mapper work:

package springbootweb04.demo;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import springbootweb04.demo.mapper.UserLoginMapper;
import springbootweb04.demo.pojo.UserLogin;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

@SpringBootTest
class DemoApplicationTests {
    @Autowired
    DataSource dataSource;

    @Test
    void contextLoads() throws SQLException {
        System.out.println(dataSource.getClass());
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

    @Autowired
    UserLoginMapper userLoginMapper;

    @Test
    void toTest(){
        List
userLogins = userLoginMapper.queryAll();
        userLogins.forEach(e -> System.out.println(e));
    }
}

Define a service interface and its implementation to encapsulate mapper calls:

package springbootweb04.demo.services;

import springbootweb04.demo.pojo.UserLogin;
import java.util.List;

public interface UserLoginServicesI {
    List
queryAll();
    int add(UserLogin userLogin);
    UserLogin queryByName(String username);
}

package springbootweb04.demo.services;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import springbootweb04.demo.mapper.UserLoginMapper;
import springbootweb04.demo.pojo.UserLogin;
import java.util.List;

@Service
public class UserLoginServicesImpl implements UserLoginServicesI {
    @Autowired
    UserLoginMapper userLoginMapper;

    @Override
    public List
queryAll() {
        return userLoginMapper.queryAll();
    }

    @Override
    public int add(UserLogin userLogin) {
        return userLoginMapper.add(userLogin);
    }

    @Override
    public UserLogin queryByName(String username) {
        return userLoginMapper.queryByName(username);
    }
}

Create a Spring MVC controller to handle login and registration requests:

package springbootweb04.demo.controller;

import springbootweb04.demo.pojo.UserLogin;
import springbootweb04.demo.services.UserLoginServicesImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class MyController {
    @Autowired
    UserLoginServicesImpl userLoginServicesImpl;

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

    @RequestMapping("/LoginSuccess")
    public String LoginSuccess(Model model, UserLogin userLogin){
        UserLogin existing = userLoginServicesImpl.queryByName(userLogin.getUsername());
        if(existing != null){
            System.out.println(existing);
            return "success";
        } else {
            model.addAttribute("data", "User not found, please register");
            return "login";
        }
    }

    @RequestMapping("/toRegister")
    public String toRegister(){
        return "register";
    }

    @RequestMapping("/RegisterSuccess")
    public String toRegisterSuccess(Model model, UserLogin userLogin){
        userLoginServicesImpl.add(userLogin);
        System.out.println("Data inserted successfully!");
        model.addAttribute("data", "Registration successful, please log in!");
        return "login";
    }
}

Place three simple Thymeleaf templates under src/main/resources/templates :

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Login</title>
</head>
<body style="background: aqua">
    <div align="center">
        <h2>Login Page</h2>
        <span th:text="${data}" style="color:red;font-size:10px"></span>
        <form method="get" action="/LoginSuccess">
            Username: <input type="text" name="username" placeholder="Enter username" required/><br/><br/>
            Password: <input type="text" name="password" placeholder="Enter password" required/><br/><br/>
            <input type="submit" value="Login"/>
        </form>
        <br/>
        <form method="get" action="/toRegister">
            <input type="submit" value="Register"/>
        </form>
    </div>
</body>
</html>

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Register</title>
</head>
<body style="background: aqua">
    <div align="center">
        <h2>Register Page</h2>
        <form method="get" action="/RegisterSuccess">
            Username: <input type="text" name="username" placeholder="Enter username" required/><br/><br/>
            Password: <input type="text" name="password" placeholder="Enter password" required/><br/><br/>
            Confirm Password: <input type="text" name="password2" placeholder="Confirm password" required/><br/><br/>
            <input type="submit" value="Register"/>
        </form>
    </div>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Success</title>
</head>
<body>
    <h2>Operation Successful</h2>
</body>
</html>

Run the application and open http://localhost:8080/toLogin to see the login page. The tutorial demonstrates a complete end‑to‑end dynamic login and registration flow using Spring Boot, MyBatis, MySQL, and Thymeleaf.

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