How to Build and Test in Maven

 

How to Build and Test in Maven?

Maven is a build automation and dependency management tool used primarily for Java projects. It uses a file called pom.xml (Project Object Model) to manage builds, dependencies, plugins, and more.

1. Building a Maven Project

Steps to Build:

Step 1: Install Maven

• Download Maven from https://maven.apache.org/download.cgi

• Set environment variables:

• MAVEN_HOME → path to Maven folder

• Add %MAVEN_HOME%\bin to PATH

• Check with:

mvn -version

Step 2: Navigate to Project Directory

cd path/to/your/project

Step 3: Run Build Commands

Common Maven Build Commands:

Command	Description
mvn validate	Validate project structure and configuration
mvn compile	Compile the Java source code
mvn test	Run unit tests using JUnit/TestNG
mvn package	Compile + bundle code into a JAR/WAR file
mvn install	Install package to local .m2 repository
mvn clean	Delete the target/ folder (cleans old builds)
mvn clean install	Clean → compile → test → package → install

2. Testing in Maven

Maven runs tests using Surefire Plugin, and the test classes must follow these conventions:

Write a Unit Test

Example with JUnit:

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;

public class CalculatorTest {
    @Test
    public void testAddition() {
        Calculator calc = new Calculator();
        assertEquals(5, calc.add(2, 3));
    }
}

Run Tests

mvn test

Skip Tests

mvn install -DskipTests

Run Specific Test

mvn -Dtest=CalculatorTest test

Plugins That Help Build & Test

Plugin	Purpose
maven-compiler-plugin	Compiles Java code
maven-surefire-plugin	Runs unit tests
maven-failsafe-plugin	Runs integration tests
maven-jar-plugin	Packages into .jar
maven-war-plugin	Packages into .war (for web apps)

Example:

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-compiler-plugin</artifactId>
      <version>3.8.1</version>
      <configuration>
        <source>11</source>
        <target>11</target>
      </configuration>
    </plugin>
  </plugins>
</build>