Step-by-Step Guide to Building a Multi-Module Spring Boot + MyBatis Project in IntelliJ IDEA

In this article we record the process of constructing a SpringBoot multi‑module project using IntelliJ IDEA, with MyBatis as the persistence layer.

Development Tools and System Environment

IDE: IntelliJ IDEA 2018.2

System: macOS

Project Directory Structure

biz layer: business logic

dao layer: data persistence

web layer: request handling

Setup Steps

1. Create Parent Project

In IDEA select File → New → Project... , choose Spring Initializr , accept defaults, and click Next through the wizard until Finish, which generates the initial project skeleton.

2. Create Sub‑Modules

Right‑click the project root, choose New → Module , select Maven, set the artifactId , and rename the module (e.g., beta-biz , beta-dao , beta-web ) for readability.

3. Run the Project

Create the entry class BetaWebApplication.java in package com.yibao.beta.web :

@SpringBootApplication
public class BetaWebApplication {
    public static void main(String[] args) {
        SpringApplication.run(BetaWebApplication.class, args);
    }
}

Add a simple controller:

@RestController
@RequestMapping("demo")
public class DemoController {
    @GetMapping("test")
    public String test() {
        return "Hello World!";
    }
}

Run the main method; the application starts on port 8080 and http://localhost:8080/demo/test returns Hello World! .

4. Configure Module Dependencies

Declare inter‑module dependencies in the parent pom.xml using dependencyManagement and dependencies . For example, beta-web depends on beta-biz , which depends on beta-dao .

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>com.yibao.beta</groupId>
            <artifactId>beta-biz</artifactId>
            <version>${beta.version}</version>
        </dependency>
        ...
    </dependencies>
</dependencyManagement>

5. Integrate MyBatis

Add mybatis-spring-boot-starter and lombok dependencies to the beta-dao module:

<dependencies>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.2</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.16.22</version>
    </dependency>
</dependencies>

Generate DAO classes with MyBatis Generator and configure datasource in application.properties :

spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://192.168.1.1/test?useUnicode=true&characterEncoding=utf-8
spring.datasource.username = test
spring.datasource.password = 123456
mybatis.mapper-locations = classpath:mybatis/*.xml
mybatis.type-aliases-package = com.yibao.beta.dao.entity

6. Resolve Bean Scanning Issues

When DemoService or UserMapper beans are not found, add package scanning to the entry class:

@SpringBootApplication(scanBasePackages = "com.yibao.beta")
@MapperScan("com.yibao.beta.dao.mapper")
public class BetaWebApplication { ... }

After adding the annotations, the application starts successfully and http://localhost:8080/demo/test returns the expected result.

Conclusion

A well‑structured multi‑module SpringBoot + MyBatis project simplifies maintenance and prepares the codebase for future micro‑service migration, with optional extensions such as a common layer, server layer (e.g., Dubbo), logback, Disconf, Redis, etc.