What is the difference between “pom” type dependency with scope “import” and without “import”?

When working with Maven, it’s crucial to grasp the concept of dependency management and how it impacts your project’s structure. One fundamental aspect is distinguishing between importing managed dependencies and normal dependencies, each serving distinct purposes within the Maven ecosystem.

Importing Managed Dependencies

Managed dependencies are imported into the dependencyManagement section of your project’s POM (Project Object Model) file. This mechanism allows you to define a centralized set of dependencies that can be shared across multiple projects. Here’s how it works:

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>other.pom.group.id</groupId>
            <artifactId>other-pom-artifact-id</artifactId>
            <version>SNAPSHOT</version>
            <scope>import</scope>
            <type>pom</type>
        </dependency>   
    </dependencies>
</dependencyManagement>

By importing a managed dependency in this manner, all dependencies defined within the dependencyManagement section of the imported POM (other-pom-artifact-id in this example) are included in your project’s dependencyManagement section. This means you can reference these dependencies in your project without explicitly specifying versions, scopes, or other details.

Normal Dependencies

On the other hand, normal dependencies are included transitively when you define a regular dependency in your POM without using the dependencyManagement section for importing. Here’s how you would typically include a normal dependency:

<dependencies>
    <dependency>
        <groupId>other.pom.group.id</groupId>
        <artifactId>other-pom-artifact-id</artifactId>
        <version>1.0.0</version>
    </dependency>
</dependencies>

In this scenario, all dependencies listed in the dependency section of other-pom-artifact-id are included in your project transitively. However, it’s crucial to note that dependencies specified in the dependencyManagement section of other-pom-artifact-id are not automatically included when importing a normal dependency.

Conclusion

Understanding the distinction between importing managed dependencies and normal dependencies is essential for efficient dependency management in Maven projects. By leveraging managed dependencies, you can streamline version control and dependency resolution across your project ecosystem, enhancing maintainability and consistency.

For more detailed information and examples, refer to the Maven documentation on Dependency Management.

By incorporating these insights into your Maven workflow, you can optimize your project’s dependency structure and ensure smooth development processes.