Lesson 47: Building & Running with Maven

Maven manages dependencies and standardizes the build lifecycle (compile, test, package) via a declarative pom.xml instead of hand-rolled scripts.

Real-time example

A team's CI pipeline runs mvn test on every pull request — the same command every developer runs locally, guaranteeing consistency.

<dependencies>
  <dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.7.3</version>
  </dependency>
</dependencies>
<!-- mvn compile / mvn test / mvn package -->

What's happening

Maven downloads the exact declared version of every dependency (and their transitive dependencies) into a shared local repository (~/.m2).

Pin dependency versions explicitly — 'latest' resolution has broken more production builds than almost anything else in Java tooling.