Top 25 Maven Interview Questions and Answers for 2024

In this interview preparation guide, you'll dive into some of the most frequently asked Maven interview questions, paired with straightforward answers to help you feel confident and ready for your next interview. Maven is a widely used build automation tool in the Java world, streamlining project management, dependencies, and builds.

Maven is a powerful build automation tool used primarily for Java projects. Understanding Maven and its functionality is crucial for any developer working in the Java ecosystem. To help prepare for Maven-related interviews, it's essential to have a strong grasp of common Maven interview questions and their corresponding answers.

Basic Maven Interview Questions for Freshers

Just starting with Maven? We've got you covered with the basics. In this section, we’ve put together some key Maven interview questions for beginners.

1. What is Maven?

Maven is a Build automation tool. This tool is primarily used in Java projects.

• It is based on the concept of POM (Project Object Model).
• It manages project dependencies, compiling source code, reporting, and documentation from the Maven repository.
• It simplifies the build process by packaging the application into distributed formats like JAR or WAR files.
• Maven provides a standardized project structure and lifecycle management.

For more details on Struts please refer to this article: Apache Maven

2. What does Build Tool mean?

A build tool is a software framework. It is used to automate the process of generating source code (if any auto-generated code is used), compiling source code, running the tests, and packaging the software components into executable formats like JAR or WAR files.

In short, it does the following tasks:

• It generates source code.
• It compiles the source code.
• It runs automated Tests.
• It packaging application into executable JAR or WAR files for deployment.
• Manages Dependencies.
• It can install the packaged code in various repositories like, Local Repository, Server Repository, and Central Repository.

3. What is the Command Line to Check Maven Version?

To check the Maven version from command line, type the below command on console:

mvn -version 

or we can also use,

mvn -v

After executing this command, it will display the Maven Version installed in our system along with Java version and Maven home directory.

4. Explain the Concept of POM in Maven.

POM stands for Project Object Model.

• It is a fundamental concept in Maven.
• It is an XML file and it is named as pom.xml.
• To build the project, it contains project metadata and configuration details used by Maven.
• It defines build settings, dependencies, and plugins etc.

5. What is a MOJO?

MOJO stands for Maven plain Old Java Object.

• MOJO is a Java class and it implements executable goal within a Maven plugin.
• Plugin is a distribution of one or more than one related MOJOs.
• MOJOs define the process, that Maven can execute during the build process, that are generating and compiling source code, packaging artifacts, and running tests.

6. What is the Difference Between Ant and Maven?

For more details on Struts please refer to this article: Difference between Maven and Ant

7. How to create a new Maven project using the command line?

To create Maven Project using command line, we need to use the below command:

mvn archetype:generate -DgroupId=your_group_id -DartifactId=your_artifact_id -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

• After running the mvn archetype:generate command, we need to select an archetype for our project.
• For this, we need to provide details such as group ID, artifact ID, and version.
• Then Maven will generate the project structure based on the selections by downloading necessary dependencies.

For more details on Struts please refer to this article: Create a New Maven Project from Command Prompt

8. How does Maven Architecture work?

Maven architecture works in three steps.

• Step 1: Read the pom.xml file.
• Step 2: Then it downloads the dependencies that are defined in pom.xml file into the local repository from the central repository.
• Step 3: After that, it creates and generates the report according to the requirement and executes the lifecycle phases, goals etc.

9. What is Maven Repositories and define the types of Maven Repository?

Maven repositories are the directories of packaged JAR files which contains all the metadata. These are mainly the locations where Maven retrieves dependencies for a project. The metadata refers to the POM files for each project. There are three types of Maven repository, that are:

• Local Repository: Local repository stores the downloaded dependencies and it is created by Maven in the local system when we run any maven command.
• Remote Repository: Remote repositories are accessed over the internet and it can be public or private.
• Central Repository: It is created by Maven Community and it is the default public repository. It contains collection of plugins and open-source libraries.

For more details on Struts please refer to this article: Maven Repositories

10. What is Maven Plugins and Why Maven plugins are used?

Maven plugins are important features of Maven. These are the extensions that provides additional functionality to the Maven build process.

• These are used to reuse the common build logic across various projects.
• The plugins allows customization and enhance the build lifecycle such as compiling code, testing, creating JAR files, packaging applications, and deploying artifacts.

We use Maven plugins to,

• Create JAR or WAR files.
• Compile Code
• Running Tests
• Packaging Application
• Create Project documentation and Reports

Maven Interview Questions for Intermediate

This section on Maven interview questions for intermediates delves deeper into its advanced features, such as custom plugins, lifecycle management, and repository configurations. Mastering these topics will demonstrate your proficiency and readiness to tackle complex project challenges.

11. What is Artifact in Maven?

An Artifact refers to a deployable component of a project in Maven.

• It can be a JAR (Java Archive), WAR (Web Application Archive), or EAR (Enterprise Archive) file produced during build process along with its metadata.
• Artifact is identified by its groupId, artifactId, and version in Maven repository.
• It is used for dependency management and it is stored in Maven repositories.

Example:

<groupId>org.springframework.security</groupId>
<artifactId>spring-security-web</artifactId>
<version>6.2.4.RELEASE</version>

12. Why is the use of the Profile Required in Maven?

In Maven, use of the profile is required to provide portability to projects.

It defines sets of configurations or dependencies that are activated under different environments (e.g. development, testing, production).

Example: We can have a profile for testing dependencies which are only activated when running tests:

<profiles>
    <profile>
        <id>test</id>
        <dependencies>
            <!-- Test dependencies -->
        </dependencies>
    </profile>
</profiles>

13. What is the Command for Offline Maven Project Creation?

The command create maven project in offline mode is:

mvn -o package

14. What is the command to Package a Maven Project?

To package a Maven project, the command is:

mvn package

15. What is the Command to Install JAR Files in the Local Repository in Maven?

To install JAR files in the local repository, the below command is used:

mvn install

To install JAR manually in the local repository, the below plugin is used:

mvn install:install-file-Dfile=<path to file>

16. How to Run the Clean Plugin Automatically during the Build in a Maven project?

To run the clean plugin automatically during the build process, we need to put the clean plugin inside the <execution> tag within the plugin configuration in the pom.xml file.

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-clean-plugin</artifactId>
            <version>3.1.0</version>
            <executions>
                <execution>
                    <id>auto-clean</id>
                    <phase>clean</phase>
                    <goals>
                        <goal>clean</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

It binds the clean goal of the clean plugin to the clean phase.

17. How to stop the propagation of plugins to child POMs in Maven?

To stop the propagation of plugins to child POMs in Maven, we should set the <inherited> element to "false" within the <plugin> configuration in the parent POM file.

set <inherited> to false.

This defines that the plugin which is defined in the parent POM is not inherited by the child POMs.

Maven Interview Questions for Experienced

If you have some experience in software development and you mastring the basics of Maven, Then in this section, you will get into advanced Maven interview questions to challenge your expertise and demonstrate your in-depth knowledge. These questions will help you showcase your ability to leverage Maven's full potential in sophisticated project environments.

18. What is the Maven Surefire plugin, and what is its role in the build process?

Maven Surefire plugin is used for running unit tests written in Java at the time of build process.

• It executes test classes and also generates reports on test results.
• The Surefire plugin is useful for automating the testing phase and maintaining the code reliability in Maven projects.

For example, we have a Maven project with JUnit test cases written in Java. To execute these tests using Surefire plugin, we need to include the plugin in the pom.xml file of our project.

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>3.0.0-M5</version>
        </plugin>
    </plugins>
</build>

After this we can run the below command:

mvn test

The above command will compile the project and execute all the unit tests using JUnit and the Surefire plugin will generate the reports accordingly.

19. What are the Three Build Life Cycles of Maven?

The three built-in build life cycles of Maven are,

• Clean: It removes the files from the previous build and cleans the project.
• Build (Default): It handles the project deployment, compilation, packaging, and installation to the local repository.
• Site: It creates the project's site documentation and generates reports.

20. What are the different Build Phases in Maven Build Lifecycle?

The Maven Build Lifecycle has different build phases that are mentioned below:

• Validate
• Test-Compile
• Test
• Package
• Integration-test
• Verify
• Install
• Deploy

For more details on Struts please refer to this article: Maven Lifecycle Phases and Basic Maven Commands

21. What are the Maven Dependency Scopes?

Dependency Scope in Maven defines the visibility and accessibility of a dependency which is already declared during different phases of the build lifecycle. Maven provides different dependency scopes to handle the use of dependencies.

• Compile Scope (default)
• Provided Scope
• Runtime Scope
• Test Scope
• System Scope
• Import Scope

22. What are the Dependencies in Maven and how to specify them?

In Maven, dependencies are the external libraries or modules.

• Maven project uses these dependencies to compile, build, and run successfully.
• To specify the dependencies in the project, we need to write them inside the pom.xml file within the <dependencies> tag section by providing the group ID, artifact ID, and version of each dependency.

23. What is Dependency Exclusion in Maven?

In Maven, Dependency Exclusion is a mechanism which is used to exclude specific transitive dependencies from the project's dependency.

• When we encounter any conflicts or any compatibility issues with dependencies, it would be useful.
• For example, if we have a dependency of older version of a library and that conflicts with the newer version required by another dependency, in this case, we can exclude the older version by using the <exclusions> tag in dependency declaration.

<dependency>
    <groupId>example.group</groupId>
    <artifactId>example-artifact</artifactId>
    <version>1.0.0</version>
    <exclusions>
        <exclusion>
            <groupId>conflicting.group</groupId>
            <artifactId>conflicting-artifact</artifactId>
        </exclusion>
    </exclusions>
</dependency>

24. How to Exclude Dependency in Maven?

In Maven, to exclude dependency, use the <exclusions> tag within the dependency declaration inside the pom.xml file.

25. What is Archetype in Maven?

Archetype refers to a Maven plugin.

• It creates the project structure as per its template.
• These archetypes are only the project templates that are generated by Maven at the time of any new project creation.