20+ Maven Interview Questions and answers. You must prepare for 2021
This tutorial covers interview questions and answers for java developers. This was also useful for experienced persons as well as for DevOps engineers. You can check my other posts on maven commands
So let’s dive deep into useful latest maven interview questions and answers.
What is Maven?. Why it is used for?
Maven is a Java build and deployment tool used for web, mobile, and desktop applications in the development process and it is declarative in the pom.xml. the configuration file contains all the dependencies and scm source.
How to know the maven version using the command line
use the following code via command line
mvn --version
What are the different build phases/goals of a maven project?
By default, It has three inbuilt goals for the life cycle of a project.
- default
- clean
- site
There are different maven phases in a build.
validate
: validation to check all things are available for buildcompile
: Compiles all java source code availablesrc//main//java
test-compile
: compiles all test Java source files located insrc//main//test
test
: Running java test casespackage
: package the project and output isjar
,war
orear
integration-test
: Running integration testsinstall
: packaged files (jar, war, or ear) to local server or folder.deploy
: packaged files to remote server or folder or repository.
All these phases are executed sequentially.
You can also run each phase using the below command.
mvn compile
What are things we can do with maven?
- Build and compile
- Site documentation
- Reporting and code quality check
- Artifacts release management
- Integration with git or svn to repository branch management
- Ship an application with different environments
How do you create a war file using maven?
use the following code via command line
use install goal to create a war file
mvn clean install
What are the different goals available in a maven project?
There are different predefined available goals.
Goal Name | Description |
---|---|
clean | remove all the files generated during the previous run under the target folder |
| |test| running unit and integration tests| |install| compiles and runs and generates war file in the target folder| |deploy| the generated war file to the target server. You need to configure server details in pom.xml | |site| Generates artifacts site documentation for maven project|
Explain POM.xml in detail?
The pom.xml
file is an important component of any maven project.
It contains important information about your project and dependencies.
POM is abbreviated as Project object model which is an XML file.
- Project detailed information like artifact name and snapshot version dependencies SVN/git repository information
- Profiles, where the Development codebase has a dev profile and production, have a different profile
- Plugin configuration Parent dependencies
How to compile java projects using maven
Maven has a predefined goal called compile
that compiles all the java files and generates class files in the target folder.
And test
goal is to compile test java files and generate class files in a target directory.
// compile source code
mvn compile
// compile test java files
mvn test
To know Maven’s direct and indirect dependencies?
Sometimes a developer needs to know project dependencies and transitive dependencies to resolve conflicts with different versions of artifacts.
mvn dependency:tree
How to compile and run the test code of the project
You can compile the test code using the test goal. if you want to run it, You need maven surefire plugin dependency. You need the configuration of test classes and resource files in pom.xml for the generation of output.
How to skip testing during the maven build process?
sometimes it is required to skip the test class running. there are many ways to skip running test classes. use -DskipTests or -Dmaven.test.skip=true options to maven command.
How to configure Proxy Settings in the maven application
Proxy for HTTP and HTTPS is configured in settings.xml
.
You can find the path of this file in C:\\Documents and Settings\\username\\.m2\\
.
If you don’t find it, You can create and add the below content to it.
Here is a sample settings.xml
example
<proxies>
<!-- Http Proxy setting configuration-->
<proxy>
<id>optional</id>
<active>true</active>
<protocol>http</protocol>
<username>proxyuser</username>
<password>proxypass</password>
<host>proxy-hostname.com</host>
<port>80</port>
<nonProxyHosts>otherhosts.com</nonProxyHosts>
</proxy>
<!-- HTTPS Proxy configuration details -->
<proxy>
<id>optional</id>
<active>true</active>
<protocol>https</protocol>
<username>username</username>
<password>password</password>
<host>proxy-hostname.com</host>
<port>80</port>
<nonProxyHosts>otherhosts.com</nonProxyHosts>
</proxy>
</proxies>
What is the difference between Maven and Ant tools?
Both are used to build and deploy java projects developed by the Apache foundation.
Here is the difference between maven
and ant
.
Maven | Ant |
---|---|
Maven contains goals | Ant contains scripts |
goals here are reusable | scripts are not reusable |
Project dependencies management tool | Only Build tool |
It has inbuilt in the lifecycle and is customizable | No lifecycle scripts |
Maven has convention rules and directory structure | There is no coding convention or project structure |
!All the configurations configure in pom.xml! build.xml contains default configuration | |
All the dependencies copied from local and remote | Dependencies are part of the project |
It is very easy to manage dependency versions | It is difficult to manage project dependency versions |
What is the difference between Maven and Gradle tools?
Maven
and Gradle
are complete project management.
Here is the difference between maven
and Gradle
.
Maven | Gradle |
---|---|
It has a pom.xml file containing project dependencies and other configurations | It is not an XML file for configuration information, But uses Domain Scripting language(DSL) |
Continuous Integration is supported | It has also support for CI tools |
Compilations are slow as incremental build not supported | Fast compilation as only modified files are compiled |
Customization is difficult | Easy customization |