Many people tense during the interview not because they are terrified but because they are anxious and unable to predict the questions they’ll be asked. You’ll understand the need to familiarize yourself with the common 30 maven interview questions and answers.
1. What Is Maven?
It’s a software application designed for project understanding and management. In other words, it can also be defined as a java build lifecycle framework. Since it can preset build circle and employ uniform director architecture, it allows automation of project build infrastructure within the shortest time possible.
2. What’s the use of the Maven plugin?
- Creates JAR files
- Compile source code files
- Create WAR files, create project reports and documentation
- Unit-test the code
3. Explain the types of Maven plugins
There are two main categories of maven plugins, build plugins and reporting plugins.
- Build plugins: we use build plugins throughout the project building process. They are configured within the <build/> element of the pom.xml file.
- Reporting plugins: they are a type of maven plugin configured within pom.xml’s <reporting/> element but are only executed during stage generation
4. What are Maven build profiles?
- Per-User: we define the per-user build profile in the settings.xml file
- Per-project: we define it within the projects pom.xml file
- Global: it’s a build profile defined within the global Maven settings.xml
5. How do we trigger or activate maven build profiles?
We can activate build profiles through the following ways
- Maven settings
- Present/missing files
- Using explicit command
- Operating system configuration
- On the foundation of environment variables
6. Explain the types of Maven repositories.
- Local repository: it’s the directory on the device of the developer and contains all dependencies in Maven. Although Maven projects depend on dependencies, they’ll only be downloaded once.
- Central repository: this repository is developed by the maven community. If your local repository doesn’t contain any dependencies, it will search across the central repository. After that, Maven downloads these dependencies into the local repository.
- Remote repository: If dependencies are hosted on web servers, the remote repository will download them. The remote repository is mainly used for internal organization projects. These dependencies will also have to be downloaded by Maven to your local repository.
7. What is dependency scope?
There are several types of dependency scopes, and they contain all dependencies that relate to your current project build stage. The different dependence scope includes;
- Compile: This default scope shows the dependencies accessible in our project’s classpath.
- Runtime: it’s a dependency scope indicating that dependency isn’t needed at the time of compilation but necessary at execution time
- System: it’s a dependency scope implying the need for specifying system path
- Provided: JKD, container, or web server delivers the dependency at runtime.
- Test: here, dependencies are made available at the execution and compilation phase
- Import: import signifies the dependency scope in the POM section is used instead of specified/identified POM
8. What are the advantages of using Maven?
Maven promotes the modular design of source code. Because it enables the management of multiple projects, it is easier for maven developers to lay their project designs into several logical parts. When all these parts are combined via dependency, it will promote modular designing of source code.
Quick Project Setup: The build .xml file in Maven isn’t complicated; it needs POM files to invoke similar jar dependencies because of the centralized POM. Developers can get free project reports and metrics, thus helping them reduce source distribution by pulling jar files from a centralized location.
9. What do you understand by the terms clean, antrun, and surefire in Maven?
- Maven clean: It’s a plugin that cleans directories and files generated during the build process by Maven. The clean plugin removes the target folder containing JAR files, documentation, and class files.
- Maven surefire plugin: During the test phase, the surefire plugin runs the application unit test at the test phase of your project build lifecycle. It generates reports in XML and plain text file format.
- Antrun: it’s a plugin that allows developers to carry out ant tasks from within Maven. Furthermore, we can embed the projects and script in the POM files.
10. Explain the phases of the Maven site lifecycle
Maven lifecycle handles anything relating to the generation of documentation. The phases include;
- Pre-site: undertake task required before the actual site generation
- Site: it helps with the development of the site generation of the project
- Post-site: this phase does tasks required to finalize project site generation. Additionally, it prepares the site for deployment.
- Site-deploy: This phase is where the project’s site decimation is deployed to the web server.
11. What is an archetype in Maven?
It’s a unique project templating toolkit in Maven. It’s an original model/pattern where similar things are made.
12. Explain the concepts of Maven
POM files: POM refers to Project Object Model, which are XML files including project information and Maven configuration information like source directory, goals, plugin, and dependencies. You need a PIOM file to run any Maven project. Before completing the configurations and functions, we’ll also need POM.xml file readable by Maven.
Dependencies & repositories: Dependencies are the external java libraries for any maven project. Repositories, on the other hand, are folders that contain bundled JAR files; your computer hard drive contains a folder known as a local repository. Dependencies from the central Maven repository are retrieved by Maven and kept in your local repository if it doesn’t exist.
Build life cycles, Goals, and Phases: Build life cycles consist of several build phases, each containing a unique goal. Phases, goals, and building lifecycles are the maven command. If a programmer asks the maven command to run, all the processes within the command will be run.
Build profiles are configuration parameters allowing developers to build projects using various setups. For instance, developers may need to build and test their project on a local computer. We can add various build profiles to the POM files via its profile elements in such a case.
Build plugins: build plugins accomplice certain tasks. Furthermore, we can add a plugin to the project POM file. Luckily, Maven is equipped with various plugins; however, they are experienced or aspiring to write their own plugins in Java.
13. In what ways does Maven help?
- Maven helps manage all processes, including documentation, building, distribution, and releasing in project management.
- It makes building a project easier by increasing project performance and build process.
- Maven enables the automatic download of dependencies such as JAR files.
- Ease access to all required project files
- It enables the building of maven projects in varying environments without worrying about processes and dependencies.
- Maven makes it easier to include new dependencies, provided you can write dependency code in the project’s POM file.
14. Why do we need optional dependency?
Optional dependency reduces the transitive burden of libraries
They are useful when Maven objects can’t be subdivided into submodules
Certain dependency is only specific to some project features; if the feature doesn’t exist, then there won’t be a need for such dependency
15. Name the order of inheritance of Maven
- #Settings
- #CLI parameters
- #Parent POM
- #Project POM
16. State the least required elements for Maven POM file
- modelVersion: should be 4.0.0
- project root
- groupId: project’s group id
- version: version of the artifact
- artifactId: artifact (project) id
17. Define Snapshot as used in Maven
This version of the maven remote repository signals the most current development copy. Maven will inspect a new Snapshot version in the remote repository for each new build.
18. Explain how Maven Architecture works.
There are three steps through which maven architecture works.
- First, it reads the projects pom.xml file.
- Next, Maven downloads dependencies within the pom.xml to your computer hard drive (local repository) from the maven central repository.
- Lastly, maven architecture creates and generates reports based on the project’s requirement and executes phases., life cycles, plugins, and goals.
19. Differentiate between MAVEN and ANT
- Maven future convention thus doesn’t require the provision of information in the pom.xml files. On the other hand, Ant lacks formal convection and requires the provision of information in the build.xml files.
- Maven is declarative while the ant is procedural;
- Maven is characterized by a life cycle, while ant doesn’t have a lifecycle.
- Maven plugins are usable while ant scripts aren’t re-usable
- Maven is mainly designed as a project management tool, while ant is specially developed as a build tool.
20. What is a build tool?
It’s a tool necessary for the application-building process. The build tool is important for the listed procedures
- Source code generation
- Source code compilation
- Installation of packaged java codes into server, central repository, or local repository
- Generation of documentation from the project code
- Package compiled codes to JAR files
21. What is Transitive Dependency
Maven automatically includes transitive dependencies to prevent the need to find out and specify the libraries required by the dependencies. Transitive dependency illustrates that if A and B are dependent and B and C are dependent, then A depends on both B and C.
22. Define dependency exclusion
Exclusion elements in Maven exclude transitive dependencies. Suppose
A and B are dependent- and B and C are also dependent, then we can mark A can be marked C as excluded.
23. What is MOJO in Maven?
MOJO is an acronym of Maven plain Old Java Object. Each mojo is a goal that can be executed in Maven, while the plugin refers to the distribution of MOJOs. With MOJOs, developers can extend a maven functionality not found in Maven.
24. Explain the Maven settings.xml file
It’s a file containing elements for defining values required for the configuration of maven execution. the key configurations found in the settings.xml file include
- Local repository configuration
- Central repository configuration
- Proxy configuration
- Remote repository configuration
25. Define Maven Artifact
Maven artifact is a JAR file deployed to maven repository. Maven can create more than one artifact like source JAR and compiled JAR. Each artifact has a unique groupID, version string, and artifact ID. With all these three, we can identify the artifact.
26. What elements create a POM.xml file?
- project
- modelVersion
- groupId
- artifactId
- version
27. state the key features of Maven
- Dependency management
- Multiple projects
- Easy to learn
- Simple to use
- fast
- Huge library
28. What are goals in Maven?
All Maven’s goals combined form what we refer to as a phase. We define every goal to perform a unique task relating to build execution and project management.
29. What are the phases of Maven Clean lifecycle?
- pre-clean
- clean
- post-clean
30. Can you perform a Maven force update?
yes, we can do a force update on Maven using the command mvn clean install –U
Conclusion
After going through all the 30 common maven interview questions and answers listed above, facing any interview panel should be easier and less tense. Most of the questions you’ll be asked during the interview session will revolve around the question we have just mentioned.
