KodeKloud Notes

In this guide, you’ll learn what Apache Maven is, why it’s essential for Java project automation, and how to leverage its lifecycle and directory conventions to streamline your build, test, and deployment processes.

What Is Maven?

Apache Maven is a powerful build automation and project management tool based on the Project Object Model (POM). By defining dependencies and build settings in a pom.xml file, Maven handles:

Downloading and managing third-party libraries
Compiling Java source code
Running unit tests
Packaging artifacts (JAR, WAR)
Deploying to local or remote repositories

Note

Your pom.xml sits at the root of your project. It controls everything from dependency versions to plugin executions.

Standard Project Structure

Maven enforces a conventional directory layout to keep builds predictable:

my-app
├── src
│   ├── main
│   │   ├── java            # Application source code
│   │   └── resources       # Configuration files & properties
│   └── test
│       ├── java            # Unit test source code
│       └── resources       # Test-specific resources
└── target                  # Compiled classes & packaged artifacts

Core Lifecycle Phases

Maven executes build steps in a predefined sequence of lifecycle phases. Common phases you’ll use daily:

Phase	Description	Outcome
validate	Ensure project is correct and all info is available	Checks `pom.xml` validity
compile	Compile application source code	Generates `.class` files in `target/classes`
test	Run unit tests	Executes tests in `src/test/java`
package	Bundle compiled code into a JAR/WAR	Produces artifact in `target/`
install	Install package to local repository	Installs to `~/.m2/repository`
deploy	Copy final artifacts to remote repositories	Publishes for sharing across teams

The image provides an overview of Maven basics, explaining its role in automating Java projects and detailing phases like validate, compile, test, package, install, and deploy. It also lists default directory paths for source code, resources, tests, and compiled outputs.

Running Tests

To compile your code and run all unit tests:

mvn test

This executes the test phase, compiling classes and running tests under src/test/java.

Packaging Artifacts

When you’re ready to create your deployable artifact:

mvn package

Maven runs up to the package phase, producing a JAR or WAR (depending on your packaging setting) in the target directory.

Warning

Ensure your pom.xml <packaging> element matches your intended artifact type (jar, war, etc.) to avoid build failures.

Integrating Maven with Jenkins

Automate your CI/CD pipeline by invoking Maven goals in a Jenkinsfile:

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        sh 'mvn clean compile'
      }
    }
    stage('Test') {
      steps {
        sh 'mvn test'
      }
    }
    stage('Package') {
      steps {
        sh 'mvn package'
      }
    }
  }
  post {
    always {
      junit 'target/surefire-reports/*.xml'
    }
  }
}

This pipeline runs through the compile, test, and package phases and archives test results automatically.

Links and References

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