What is a transitive Maven dependency?

Johan picture Johan · Jan 18, 2017 · Viewed 28.2k times · Source

This question is about to clarify what exactly a transitive dependency is and how it works at very high level in Maven.

My definition: in a dependency tree like A --> B --> C, C is a transitive dependency for A. Assume B has scope compile within A.

If C has scope compile within B, then declaring B as dependency of A suffices to build A with Maven. But if C has scope provided within B then, when Maven builds A, the building will not automatically compile A against C unless A declares C among its dependencies.

Is this correct?

Answer

carlspring picture carlspring · Jan 18, 2017

Your assumption is correct.

There are two types of Maven dependencies:

  • Direct: These are dependencies defined in your pom.xml file under the <dependencies/> section.

  • Transitive: These are dependencies that are dependencies of your direct dependencies.

Dependencies with provided scope are meant to:

  • Either be excluded from the final artifact (for example, for war files you would not want to include servlet-api, servlet-jsp, etc)
  • Or overriden -- where the project that inherits these defines a version and/or overrides the scope