A Multi-module Maven Project is a software architecture pattern that allows developers to split a large project into multiple interconnected sub-modules, all managed by a single parent project.
This parent-child Maven structure aligns well with microservices architecture. For example, a parent project can contain gateway and auth-service sub-modules. After packaging, these two modules can be deployed and maintained separately.
It’s important to note that this parent-child relationship is for build management, not a functional hierarchy. The parent POM centralizes dependency management, but it doesn’t mean gateway necessarily depends on auth-service.
Programmatic Dependencies: If the gateway module needs to use classes from auth-service, you would add a dependency in its pom.xml. However, in a typical microservices setup, gateway and auth-service communicate via HTTP APIs or OAuth tokens, eliminating the need for a direct JAR dependency.
A typical multi-module project structure in Maven looks like this:
workspace/
├─ pom.xml <-- Parent POM, defines dependencyManagement, pluginManagement, versions
├─ gateway/ <-- Child module
│ └─ pom.xml
└─ auth-service/ <-- Child module
└─ pom.xml
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