Apache Maven Tutorial

1. Introduction

Building a software project typically consists of such tasks as downloading dependencies, putting additional jars on a classpath, compiling source code into binary code, running tests, packaging compiled code into deployable artifacts such as JAR, WAR, and ZIP files, and deploying these artifacts to an application server or repository.

Apache Maven automates these tasks, minimizing the risk of humans making errors while building the software manually and separating the work of compiling and packaging our code from that of code construction.

In this tutorial, we’re going to explore this powerful tool for describing, building, and managing Java software projects using a central piece of information — the Project Object Model (POM) — that is written in XML.

2. Why Use Maven?

The key features of Maven are:

mvn archetype:generate \
  -DgroupId=com.baeldung \
  -DartifactId=baeldung \
  -DarchetypeArtifactId=maven-archetype-quickstart \
  -DarchetypeVersion=1.4 \
  -DinteractiveMode=false

The groupId is a parameter indicating the group or individual that created a project, which is often a reversed company domain name. The artifactId is the base package name used in the project, and we use the standard archetype. Here we are using the latest archetype version to ensure our project is created with updated and latest structure.

Since we didn’t specify the version and the packaging type, these will be set to default values — the version will be set to 1.0-SNAPSHOT, and the packaging will be jar by default.

*If you don’t know which parameters to provide, you can always specify interactiveMode=true, so that Maven asks for all the required parameters.*

After the command completes, we have a Java project containing an App.java class, which is just a simple “Hello World” program, in the src/main/java folder.

We also have an example test class in src/test/java. The pom.xml of this project will look similar to this:

<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.baeldung</groupId>
    <artifactId>baeldung</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>baeldung</name>
    <url>http://www.example.com</url>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

<build>
    <sourceDirectory>src</sourceDirectory>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.11.0</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>3.1.0</version>
            <configuration>
                <mainClass>com.baeldung.java.App</mainClass>
            </configuration>
        </plugin>
    </plugins>
</build>

The first plugin, maven-compiler-plugin, is responsible for compiling the source code using Java version 1.8. The exec-maven-plugin searches for the mainClass in our project.

To execute the application, we run the following command:

mvn exec:java

6. Conclusion

In this article, we discussed some of the more popular features of the Apache Maven build tool.

All code examples on Baeldung are built using Maven, so you can easily check our GitHub project website to see various Maven configurations.