Maven Interview Questions

Maven Interview Questions and Answers: Apache Maven is a popular tool for building and managing Java projects. It helps with tasks like handling project dependencies and testing. Many companies need skilled people who know how to use Maven well.

If you’re a developer or software engineer, it’s important to prepare for Maven interview questions to demonstrate your knowledge.

Frequently Asked Maven Interview Questions

• Why Maven? Explain what Maven is. How does it work?
• Can you give some basic commands used in the Maven project?
• What is the difference between a group ID and an artifact ID?
• Explain what the Maven artifact is.
• What is Archetype?
• List out what aspects Maven Manages.
• Mention the difference between Apache Ant and Maven.
• In Maven, what are the two setting files called, and what is their location?
• List the build, source, and test source directory for POM in Maven.
• Where do you find the class files when you compile a Maven project?
• Explain what would the “jar: jar” goal do?
• For POM, what are the minimum required elements?
• Explain how to execute the test classes in Maven.
• What is the command in Maven to generate an Archetype?
• What are the different setting files in Maven? Where will you find these files? (Zensar Technologies)
• What are the main elements we can find in settings.xml?
• How will you check the version of Maven in your system?
• How will you verify if Maven is installed on Windows?
• Maven commands to execute, debug, compile
• What is the current version of Maven used?
• How to pass TestNG in maven file.
• Settings.xml in Maven
• Explain the tags present in the testng.xml file
• Explain your project folder structure. Or Explain your framework?
• What is POM? What advantages and disadvantages?
• What are the main required elements in the POM file?
• What command will you use to package your Maven project?
• What is the format of the fully qualified artifact name of a Maven project?
• Where will you find the class files after successfully compiling a Maven project?
• What are the default locations for source, test and build directories in Maven?
• What is the result of the jar: jar goal in Maven?
• How can we get debugging or error messages from Maven’s execution?
• What are the differences between Gradle and Maven?
• What is the difference between Inheritance and Multi-module in Maven?
• What is Build portability in Maven?
• What are the main features of Maven?
• What areas of a project can you manage using Maven?
• What are the main advantages of Maven?
• What is the difference between a Release version and a SNAPSHOT version in Maven?
• Sometimes, Maven compiles the test classes but doesn’t run them. What could be the reason for it?
• How can we skip the running of tests in Maven?
• How does Maven search for JAR corresponding to a dependency?
• Can we create our own directory structure for a project in Maven?
• What are the responsibilities of a Build tool like Maven?
• Why should we not store jars in CVS or any other version control system other than the Maven repository?
• Can anyone upload JARS or artifacts to Central Repository?

Life Cycle

• What are the phases in the Build lifecycle in Maven? Explain according to your project.
• What is the difference between Maven Test and Maven Install?

POM

• What is the use of pom.xml?

Plugins

• Why Maven Plugins are used?
• Have you used the Maven Surefire plugin? If yes, where and why?
• How to run the clean plugin automatically during the build?
• What are the main uses of a Maven plugin?
• How will you find the version of a plugin being used? define these profiles?

Dependencies

• How will you handle dependencies in Maven at run time?
• What are the different dependency scopes in Maven?
• Explain how you can exclude dependency.
• How can we exclude a dependency in Maven?
• What are Excluded dependencies in Maven?
• What are Optional dependencies in Maven?
• What is a transitive dependency in Maven?

Profile

• Mention how profiles are specified in Maven.
• How do you create and execute a profile in Maven?

Repository

• Explain what Maven Repository is. What are their types?
• What is a Repository in Maven?
• What are the different types of repositories in Maven?
• What is a local repository in Maven?
• What is a central repository in Maven?
• What is a Remote repository in Maven?

Scenarios

• Today, we executed some tests using Maven, but tomorrow, when you see that someone deleted all dependencies from the POM file, will you be able to execute tests?
• Consider you have to write a test/suite for different environments(QA, preproduction, production) and pass a different set of data for each environment. How will you do it using the maven file(Pom.xml)?
• How do you work with Maven offline? If there is no internet connection for security reasons, then how will you add maven dependencies offline to the maven project?
  Ans: If this is the situation, then there is a Nexus location where all the dependencies as per the need have already been downloaded. You can use it as a Maven proxy and download it.

Maven Interview Questions With Answers

<dependencies>
    <dependency>
        <groupId>com.example</groupId>
        <artifactId>example-dependency</artifactId>
        <version>1.0.0</version>
    </dependency>
</dependencies>

Interview Questions On Maven

How do you manage dependencies using Maven?
Managing dependencies with Maven is easy. Here’s how it works:
First, you need to specify the dependencies your project needs in the Project Object Model (POM) file. The POM is a configuration file for your project, and it has all the details about your project, including the dependencies it needs. To specify a dependency, you just need to add a section to the POM file with the name and version of the dependency you want to use.

After you’ve specified your dependencies, Maven will automatically download and include them in the build process. This simplifies the process of including external libraries and ensures that all necessary dependencies are present.

But it gets even better! Maven also handles transitive dependencies for you. Transitive dependencies are dependencies that your project’s dependencies might depend on. It can be confusing to keep track of all these dependencies manually, but Maven takes care of it for you. It will automatically download and include any transitive dependencies your project needs, so you don’t have to worry about it.

In short, managing dependencies with Maven is convenient and helps streamline the build process. You just specify the dependencies you need in the POM file, and Maven does the rest.

2. How do you configure Maven to build and deploy a project?
First, you’ll need to create a Project Object Model (POM) file for your project. The POM is a configuration file that tells Maven how to build and deploy your project. In the POM, you’ll specify things like the dependencies your project needs, the build plugins you’re using, and the build lifecycle.

Once you have your POM set up, you can use Maven’s command-line interface (CLI) to build and deploy your project. To build the project, you can use the “mvn clean install” command, which will compile the source code, run any tests, and create a JAR or WAR file (depending on the type of project you’re building).

To deploy the project, you can use a Maven plugin like the Tomcat plugin. The Tomcat plugin allows you to deploy your project to a Tomcat server with a single command. You’ll just need to specify the URL of your Tomcat server in the POM file, and Maven will take care of the rest.

Overall, configuring Maven to build and deploy a project is a straightforward process. Just create a POM file, use the CLI to build the project, and use a Maven plugin to deploy it.

3. Can you describe the Maven build lifecycle?
The Maven build lifecycle refers to the sequence of steps that Maven follows to build a project. There are three main build lifecycles in Maven: clean, default, and site.

The clean life cycle is used to clear up after a build. it has a single phase called “pre-clean,” which is executed before the project is cleaned.

The default lifecycle is the most commonly used lifecycle in Maven. It consists of the following phases:

• Validate: checks that the project is correct and all required information is available
• Compile: compiles the source code
• Test: runs the tests
• Package: packages the compiled code into a JAR or WAR file
• Install: installs the package in the local repository
• Deploy: deploys the package to a remote repository

The site lifecycle is used to generate the project’s site documentation. It has the following phases:

• Pre-site: executes processes needed before the site is generated
• Site: generates the site
• Post-site: executes processes needed after the site is generated
• site-deploy: deploys the generated site to a remote web server

In summary, the Maven build lifecycle is the series of steps that Maven follows to build a project. The clean, default, and site lifecycles are the three main lifecycles in Maven, and each one has a specific set of phases that it goes through.

What is the structure of a Maven project?
A Maven project follows a specific directory structure that is defined by the Maven project object model (POM). This structure allows Maven to understand how to build and manage the project.

The root directory of a Maven project contains the project’s POM file, which is named “pom.ml” and defines the project’s configuration, dependencies, builds settings, and other information. The POM file is the most important file in a Maven project, and it must be located at the root of the project.

The root directory of a Maven project also contains several subdirectories that are used to store the project’s source code, resources, and build artifacts. The most important of these subdirectories are:

• src/main/java: This directory contains the project’s main source code.
• src/main/resources: This directory contains the project’s main resources, such as property files and configuration files. src/test/java: This directory contains the project’s test source code.
• src/test/resources: This directory contains the project’s test resources.
• target: This directory contains the project’s build artifacts, such as compiled classes and packaged JAR files.

By adhering to this directory structure, you can easily manage and build your Maven project using the standard Maven tooling.

How do you specify dependencies in a Maven project?
You must include dependencies in the project’s POM file in order to declare them in a Maven project. A Maven project’s setup, dependencies, build settings, and other details are specified in the POM file, an XML file. Its name is “pom.xml,” and it is found in the project’s root.

You must include a “dependency” element in the POM file in order to add a dependency to a Maven project. The following details should be included in the “dependency” element:

The dependency groupid is a distinctive identity for the group that created the dependency.
The dependency’s artifactid serves as its specific internal identification number.
The dependency’s version: You want to include this version of the dependency in your project.
Here’s an example of how you might specify a dependency in a Maven project:

<dependencies>
	<dependency>
		<groupld>com.example</groupld>
		<artifactid › example-dependency</artifactid>
		<version>1.0.0</version>
	</dependency>
</dependencies>

How do you run a Maven build?
To run a Maven build, you’ll need to have Maven installed on your system and navigate to the root directory of your Maven project in your terminal. Once you’re in the root directory of your project, you can run a Maven build by using the “mvn” command followed by the build goal that you want to execute.

Here are some examples of Maven builds goals that you might run:

• “mvn clean”: This goal cleans the project’s build artifacts.
• “mvn compile”: This goal compiles the project’s source code.
• “mvn test”: This goal runs the project’s tests.
• “mvn package”: This goal packages the project’s code and resources into a distributable format, such as a JAR or WAR file.
• “mvn install”: This goal installs the project’s artifacts in the local repository, making them available for other projects to use.

You can also specify additional build options and properties when running a Maven build by using command-line arguments. For example, you can use the “-D” flag to specify a property or the “-p” flag to specify a profile.

For more information about running Maven builds and the available build goals and options, you can consult the Maven documentation or ask for additional help. 

What is the Maven Central repository, and how is it used?
The Maven Central repository is a collection of Java libraries and artifacts that are made available to Maven users. It serves as a central location for developers to find and use open-source libraries and dependencies for their Maven projects. When you include a dependency in your Maven POM file, Maven will automatically search the Central repository for the corresponding library or artifact and download it if it is not already present in your local repository. This can save you time and effort when setting up your project dependencies, as you don’t have to manually download and install each library.

The Central repository is maintained by the Apache Foundation and is widely used by the Java community. it is considered a best practice to use the Central repository as much as possible, as it helps to ensure that your dependencies are well-maintained and up-to-date.

How do you use Maven to build and deploy a project with external dependencies?
To use Maven to build and deploy a project with external dependencies, you will need to do the following:

Create a new Maven project for your project. This can be done using the “mvn archetype: generate” command, which will generate a basic project structure for you.

Add the dependencies of your project to the POM file of your project. This can be done by adding a dependencies element to the POM file and specifying the dependencies within the dependencies element.

Create the source code for your project. This will typically include Java classes and any other resources that your project needs.

Build the project using Maven. This can be done by running the “mvn package” command, which will compile the source code and package it into an artifact (e.g., a WAR or JAR file).

Deploy the artifact to a server. This can be done by copying the artifact to the appropriate directory on the server or by using a tool such as Jenkins to automate the deployment process.

By following these steps, you can use Maven to build and deploy a project with external dependencies. Maven can simplify the build and deployment process by handling tasks such as dependency management and package creation, allowing you to focus on writing the code for your project.

How can you override the version of a dependency in Maven?
You can override the version of a dependency using a property. Properties in Maven are values that can be referenced from within the pom.xml file using the syntax “$(propertyName)*. For example:

	<properties>
		<example.library.version>2.0.0</example.library.version>
	</properties>
	<dependency>
		<groupid>com.example</groupld>
		<artifactid>example-library</artifactid>
		<version>$(example.library.version)</version>
	</dependency>

In this case, the version of the “example-library” dependency will be 2.0.0, because it is specified in the “example.library.version” property.

How do you specify a profile in Maven, and how do you activate it?
In Maven, you can use profiles to specify different build configurations for different environments or scenarios. Profiles are defined in the pom XML file using the element and can be activated in a number of ways.

To define a profile in Maven, you can use the following syntax:

<profiles>
	<profile>
		<id>profile-name</id>
		<build>
		</build»
	</profile>
</profiles>
<|-- configuration for this profile goes here ->

You can then activate a profile in one of the following ways:

By specifying the -P command-line option when running Maven, followed by the profile ID. For example:
mvn clean install -P profile-name
By setting the activeProfiles element in the settings.XML file. For example:

<settings>
	<activeProfiles>
	<activeProfile>profile-name</activeProfile>
	</activeProfiles>
</settings>

By specifying the MAVEN_OPTS environment variable with the -P option. For example:

MAVEN_OPTS=-P profile-name

You can also specify activation conditions for profiles, which allow Maven to automatically activate a profile based on certain criteria, such as the presence of a system property or the value of an environment variable.

How do you configure the build output directory in Maven?
To determine the location where Maven will output compiled class files and other build artifacts, you can use the <outputDirectory› element inside the <build› element of your pom xml file. An example of how to use this element is:

<build>
	<outputDirectory>build/classes</outputDirectory>
</build>

This will configure Maven to place the build output in the build/classes directory. By default, Maven uses the target directory as the build output directory, but you can override this by specifying a different directory in the pom.xml file.

Using the element, you can also specify a separate output directory for test class files and other test artifacts.

How do you specify environment variables for Maven?
Using the -e flag while executing Maven from the command line allows you to provide environment variables. The following command, for instance, could be used to set the foo environment variable to bar:

mvn -e -Dfoo=bar clean install

You can also set environment variables in the operating system where Maven is running. These environment variables can then be accessed from within the POM or your project’s code using standard Java system property access methods.

Keep in mind that environment variables set using the -e flag will only be available for the current Maven execution. To make environment variables permanently available, you’ll need to set them in the operating system where Maven is running.

It’s also worth noting that environment variables have a lower priority than system properties, so if you have a system property and an environment variable with the same name, the system property will take precedence.

How do you specify a property in Maven that can be overridden at build time?
To specify a Maven property that can be changed during the build process, you can utilize the -D flag when running Maven from the command line, similar to how you would with any other system property. As an example, to set the foo property to bar, you can use the command:

mvn -Dfoo=bar clean install

This will set the foo property to bar for the current build. However, you can also specify a different value for foo when running the build, like this:
mvn -Dfoo=baz clean install

This will use baz in place of the value of foo that was set in the POM.

Additionally, it is possible to define default values for properties in the POM, which may be overridden by specifying the property in the settings xml file or with the -D switch. This can be helpful if you want to provide a property with a default value but let users change it when creating the project.
Example: mvn test -Dsurefire.suiteXmlFiles -DbrowserName=firefox

How do you configure the Maven Surefire Plugin to run Selenium tests?
In order to run Selenium tests using the Maven Surefire Plugin, you must first add the plugin to your pom.xml file. To do this, you can insert the below code snippet within the section:

<plugin>
	<groupid>org.apache. Maven.plugins</groupid>
	<artifactid> maven-surefire-plugin
	</artifactld>
	<version> 3.0.0-M3</version>
	<configuration »
		<suiteXmiFiles>
			<suiteXmiFile>testng.xml
			</suiteXm|File>
			</suiteXmiFiles>
	</configuration>
</plugin>

Next, you will need to create a testng.xml file in the root directory of your project. This file will contain the configuration for your Selenium tests, including the test class names and any parameters you want to pass to your tests.

To run your Selenium tests using the Maven Surefire Plugin, open a terminal and navigate to the root directory of your project. Then, simply run the following command: mvn test.

This should trigger the Maven Surefire Plugin to run your Selenium tests using the configuration specified in your testng.xml file. This is a common Maven interview question for Selenium testers, so it’s a good idea to have a solid understanding of how to configure the Maven Surefire Plugin to run Selenium tests.

How do you configure Maven to use a custom version of the Maven artifact model?
To customize the version of the Maven artifact model that Maven uses, you’ll need to update the maven-artifact dependency in your pom.xml file’s section. The Maven artifact model includes the interfaces and classes that represent Maven artifacts like a jar, war, and ear files. To specify version 3.8.0 of the Maven artifact model, you can include the following in your pom.xml file:

<dependencies>
	<dependency>
		<groupld>org.apache.maven</groupld>
		<artifactid>maven-artifact
		</artifactld>
		<version>3.8.0</version>
	</dependency>
</dependencies>

It’s important to note that the Maven artifact model is automatically included as a dependency in your project when you create a new Maven project using the archetype:generate goal. However, the default version is set to the latest stable release at the time the project was created. You’ll need to update the maven-artifact dependency if you want to use a different version.

How do you resolve dependency conflicts in a Maven project?
Answer: Maven uses the nearest definition strategy, where the version of the dependency declared closest to the project in the dependency tree takes precedence. Understanding the dependency hierarchy and utilizing the dependency:tree command helps identify and resolve conflicts.

Explain how you would perform an offline build using Maven.
Answer: Maven allows offline builds by using the -o or –offline option. This prevents Maven from attempting to connect to remote repositories, relying on the locally cached dependencies. This is useful in scenarios with limited or no internet connectivity.

Can you customize the Maven build lifecycle, and if so, provide an example?
Answer: Yes, the build lifecycle can be customized using plugins. For instance, the exec-maven-plugin allows the execution of arbitrary commands during the build process. Configuring it in the section of the POM file enables the execution of custom scripts or commands.

What are Maven snapshot releases, and when should they be used?
Answer: Snapshot releases are development versions of a project. They have a unique version number with the “-SNAPSHOT” suffix. Snapshots are useful during development to allow continuous integration systems to pick up the latest changes. However, they should be avoided in release versions.

How do you handle a multi-module Maven project, and what benefits does it offer?
Answer: In a multi-module project, Maven can build multiple projects within the same hierarchy. Each module represents a different subproject, and the parent POM coordinates the build process. This structure promotes code organization and reuse and simplifies the management of complex projects. 

Maven Commands List

As automation testers, we frequently use Maven to manage the build process and dependencies for test automation projects. Maven commands are essential for automation testing workflow, enabling streamlining the build process, managing dependencies, and easily deploying test automation projects.

• mvn clean: This command is used to clean the project’s target directory.
• mvn compile: This command is used to compile the project source code.
• mvn package: This command is used to package the project into a JAR file.
• mvn install: This command is used to install the package into the local repository.
• mvn deploy: This command is used to deploy the package to a remote repository.
• mvn test: This command is used to run the project unit tests.
• mvn verify: This command is used to run the project integration tests.
• mvn site: This command is used to generate the project’s site documentation.
• mvn help:effective-pom: This command is used to display the project’s effective POM.
• mvn help:describe: This command is used to display the details of a mojo.
• mvn archetype:generate: This command is used to generate a project from an archetype.
• mvn help:active-profiles: This command is used to list the active profiles in the project.
• mvn dependency:tree: This command is used to display the project’s dependency tree.
• mvn help:plugin: This command is used to display information about a specific plugin.
• mvn help:system: This command is used to display information about the system.
• mvn help:effective-settings: This command is used to display the project’s effective settings.
• mvn help:describe: This command is used to display information about a specific mojo.
• mvn clean test: This command is used to clean the project and then run the unit tests.
• mvn site:run: This command is used to generate the project’s site documentation and launch a web server to view it.
• mvn help:all-profiles: This command is used to list all the profiles in the project.
• mvn dependency:analyze: This command is used to analyze the project’s dependencies.
• mvn help:system-properties: This command is used to display system properties that can be used in the project.
• mvn help:evaluate: This command is used to evaluate an expression in the project’s POM.
• mvn help:descriptor: This command is used to display the project descriptor.
• mvn help:active-profiles: This command is used to list the active profiles in the project.
• mvn help:plugin-prefix: This command is used to display the list of available plugin prefixes.