What is Maven | How to create MAVEN Environment in details

 What is Maven?

Apache Maven is a build automation and project management tool primarily used for Java projects. It is based on a Project Object Model (POM) file (pom.xml) which defines a project’s structure, dependencies, plugins, and build lifecycle.

📂 POM (Project Object Model)

The heart of Maven is the pom.xml file which defines:

• Project metadata (name, version, etc.)

• Dependencies

• Plugins

• Build instructions

Example of pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 

                             http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>

    <artifactId>myapp</artifactId>

    <version>1.0-SNAPSHOT</version>

    <dependencies>

        <!-- Your dependencies go here -->

    </dependencies>

</project>

✅ Apache Maven Installation on Windows

🛠️ Prerequisites

• Java JDK (Java Development Kit) must be installed.

• Set JAVA_HOME environment variable.

1. Download Maven

• Visit the official Apache Maven website:
  👉 https://maven.apache.org/download.cgi

• Click on Binary zip archive to download (e.g., apache-maven-3.9.6-bin.zip)

2. Extract the Zip File

• Extract it to a preferred location, e.g.:
  C:\Program Files\Apache\Maven

3. Set Environment Variables

a) MAVEN_HOME

• Open System Properties → Environment Variables

• Under System variables, click New:

  • Variable name: MAVEN_HOME

  • Variable value: C:\Program Files\Apache\Maven\apache-maven-3.9.6 (adjust path if different)

b) Update the PATH variable

• In the same Environment Variables window:

  • Find the variable named Path

  • Click Edit → New → Add:

    
    %MAVEN_HOME%\bin
    

---

4. Verify Installation

• Open Command Prompt

• Type:

mvn -version

✅ 1. Create a New Maven Project

Option 1: Using Command Line (Recommended)

Run this in Command Prompt or Terminal:

mvn archetype:generate -DgroupId=com.test -DartifactId=MyFirstMavenProject -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

📁 This creates a basic Maven project with:

• Group ID: com.example

• Artifact ID: MyFirstMavenProject

• Java source files

• pom.xml (project descriptor)

  ✅ 2. Project Structure

  Once created, your folder structure will look like:

  css
  
  MyFirstMavenProject/
  ├── pom.xml
  └── src
      ├── main
      │   └── java
      │       └── com
      │           └── example
      │               └── App.java
      └── test
          └── java
              └── com
                  └── example
                      └── AppTest.java
  

  ---

  ✅ 3. View or Edit the Code

  📄 App.java

  Located at: src/main/java/com/example/App.java

  java
  
  package com.example;
  
  public class App {
      public static void main(String[] args) {
          System.out.println("Hello, Maven World!");
      }
  }
  

  ---

  ✅ 4. Build the Project

  Open terminal or command prompt in your project directory:

  bash
  
  cd MyFirstMavenProject
  mvn clean install
  

  ✅ This will:

  • Compile your Java code

  • Run unit tests (if any)

  • Package the app into a .jar file

  ---

  ✅ 5. Run the Project

  You’ll find the .jar file in the target/ directory:

  bash
  
  cd target
  java -cp MyFirstMavenProject-1.0-SNAPSHOT.jar com.example.App
  

  Expected Output:

  
  Hello, Maven World!
  

  ---

  ✅ 6. (Optional) Add Dependencies to pom.xml

  You can add external libraries like this:

  xml
  
  <dependencies>
      <dependency>
          <groupId>org.apache.commons</groupId>
          <artifactId>commons-lang3</artifactId>
          <version>3.12.0</version>
      </dependency>
  </dependencies>
  

  Then run:

  
  mvn install

Basic Maven Commands:

✅ Basic Maven Commands

Command	Description
mvn -v	Check Maven version
mvn clean	Deletes the target/ directory (cleans previous build)
mvn compile	Compiles the source code of the project
mvn test	Runs unit tests
mvn package	Compiles, tests, and packages the code into a .jar or .war
mvn install	Installs the .jar or .war into your local Maven repository (~/.m2)
mvn deploy	Deploys the package to a remote repository (e.g., Nexus, Artifactory)
mvn validate	Validates if the project is correct and all info is available
mvn verify	Runs any checks (like integration tests) before packaging

✅ Step-by-Step: Jenkins + Maven Integration

---

🔧 Step 1: Install Maven in Jenkins

1. Go to Jenkins Dashboard → Manage Jenkins → Global Tool Configuration

2. Scroll to Maven section → click Add Maven

3. Name it something like: Maven_3.9.6

4. Choose:

   • ✅ Install automatically (recommended)

   • Or manually provide Maven home path

📌 Save changes.

---

✅ Option 1: Freestyle Jenkins Job

🎯 Goal: Run Maven commands (clean, compile, test, package, install)

1. Create Job

• Go to Jenkins → New Item → Freestyle project

• Name: MavenBuildJob

2. Configure Source Code (optional)

• Under Source Code Management, connect your GitHub/Git repo.

3. Add Maven Build Step

• Scroll to Build → Add build step → Invoke top-level Maven targets

• In Goals, enter:

clean install

You can replace it with compile, package, etc.

• Choose Maven version you configured earlier: Maven_3.9.6

4. Save and Run

• Click Build Now

• Check console output.

---

✅ Option 2: Jenkins Pipeline (Recommended)

📄 Example: Jenkinsfile with all Maven commands

pipeline {
    agent any

    tools {
        maven 'Maven_3.9.6'   // Name from Global Tool Configuration
        jdk 'JDK17'           // Ensure JDK is configured
    }

    stages {
        stage('Checkout') {
            steps {
                git 'https://github.com/your-username/your-java-project.git'
            }
        }

        stage('Clean') {
            steps {
                sh 'mvn clean'
            }
        }

        stage('Compile') {
            steps {
                sh 'mvn compile'
            }
        }

        stage('Test') {
            steps {
                sh 'mvn test'
            }
        }

        stage('Package') {
            steps {
                sh 'mvn package'
            }
        }

        stage('Install') {
            steps {
                sh 'mvn install'
            }
        }

        stage('Run App') {
            steps {
                sh 'java -cp target/*.jar com.example.App'
            }
        }
    }
}

for windows:

✅ Jenkins Pipeline Script for Windows

Here is a complete Jenkinsfile for a typical Maven-based Java project:

📄 Windows-Compatible Jenkinsfile

groovy

Copy

Edit

pipeline {

    agent any

    tools {

        maven 'Maven_3.9.6'   // This name should match what you configured in Jenkins Global Tools

        jdk 'JDK17'           // Also configure JDK17 in Global Tools

    }

    stages {

        stage('Checkout') {

            steps {

                git 'https://github.com/your-username/your-java-project.git' // Replace with your repo

            }

        }

        stage('Clean') {

            steps {

                bat 'mvn clean'

            }

        }

        stage('Compile') {

            steps {

                bat 'mvn compile'

            }

        }

        stage('Test') {

            steps {

                bat 'mvn test'

            }

        }

        stage('Package') {

            steps {

                bat 'mvn package'

            }

        }

        stage('Install') {

            steps {

                bat 'mvn install'

            }

        }

        stage('Run Application') {

            steps {

                bat 'java -cp target\\*.jar com.example.App'  // Change `com.example.App` to your main class

            }

        }

    }

}