Maven - Build & Test Project

Maven is a build automation tool used for Java projects. It simplifies the process of project building, dependency management, and project documentation. This guide will walk you through the steps of building and testing a Maven project.

Key Concepts:

• Project Object Model: It is the heart of the Maven project because it includes project configuration and required dependencies project artifacts and other things.
• Dependencies: Libraries or other projects required to build your project.
• Plugins: Extension to Maven to execute various build tasks such as compiling code, running test cases, and others.
• Goals: A single task that contributes to the build and test process.
• Life cycle: A sequence of phases that includes default phases like validate, compile, test, package, verify, install, and other phases.

Workflow Diagram:

Below we provide how internally the maven build process is done with testing test cases also.

graph TB
    subgraph Project Structure
        A[Project Source Code]
        A1[pom.xml]
        A2[src/main/java/com/example/App.java]
        A3[src/test/java/com/example/AppTest.java]
    end
    
    subgraph Maven Commands
        B[mvn validate]
        C[mvn compile]
        D[mvn test]
        E[mvn package]
        F[mvn verify]
        G[mvn install]
        H[mvn deploy]
    end

    A --> B
    B --> C
    C --> D
    D --> E
    E --> F
    F --> G
    G --> H

Description of Each Phase:

• Validate: The Maven Ensures the project is valid and all required information is available.
• Compile: Maven Build tool Compiles the source code.
• Test: Executes tests to validate code correctness
• Package: Packages the compiled code into a distributed formats like JAR, WAR and other formats
• Verify: Performs additional checks, typically for integration testing.
• Install: Installs the package to the local Maven repository.
• Deploy: Deploys the package to a remote repository for use by other projects.

Build and Test Maven Project

Here we created a sample Maven project using Spring Initializr with the required dependencies for the project. Below is the step-by-step process for building and testing a Maven project using Maven commands.

Step 1: Create a Sample Maven Project

First create a sample maven project by using your favorite IDE. Here, we use Spring Tool Suite and select required dependencies for this project. Below are the dependencies.

Dependencies:

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

Project Structure:

Step 2: Write Sample Test Cases

Once project is created successfully, write sample test cases in the test class which is located in src/test/java location in the project.

MavenbuildApplicationTests.java:

package com.app;

import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class MavenbuildApplicationTests {

    @Test
    void contextLoads() {
    }

    @Test
    public void shouldAnswerWithTrue() {
        assertTrue(true);
    }
}

Step 3: Validate the Project

Now, open the command prompt and redirect to your project folder and run the following command to validate the project:

mvn validate

Output:

Step 4: Compile the Source Code

Once successfully validated the project, we need to compile the source code.

mvn compile

Output:

Step 5: Run Unit Tests

Now, Run the unit tests once compilation is completed.

mvn test

Output:

Step 6: Package the Compiled Code

Now Package the compiled code.

mvn package

Output:

Step 7: Run Integration Tests and Verify

Run integration tests and perform additional verifications

mvn verify

Output:

Maven Build Success:

Step 8: Install the Package to Local Repository

Now, Install the package to Local Repository.

mvn install

Output:

Maven Build Success:

Step 9: Deploy the Package to Remote Repository

Now Deploy the package to Remote Repository.

mvn deploy

Output:

Maven Build Success: