Building with Maven

This guide covers building, testing, and packaging the Authentication Test API using Apache Maven.

Project Location

All Maven commands should be run from the API_server/ directory where the pom.xml file is located.

Maven Lifecycle

Maven uses a standard build lifecycle with these main phases:

clean → validate → compile → test → package → verify → install → deploy

Basic Build Commands

Clean Build

Remove all generated files and start fresh:

cd API_server
mvn clean

This deletes the target/ directory within API_server/.

Compile

Compile the source code without running tests:

cd API_server
mvn compile

Output: Compiled classes in API_server/target/classes/

Run Tests

Execute unit tests:

cd API_server
mvn test

Package

Create the WAR file:

cd API_server
mvn package

Output: API_server/target/authentication-test-api.war

Full Build

Clean, compile, test, and package in one command:

cd API_server
mvn clean package

This is the most common build command.

Development Mode

Liberty Dev Mode

Run the application with hot reload:

cd API_server
mvn liberty:dev

Features: - Hot Reload: Automatically recompiles and redeploys on code changes - Test on Save: Runs tests when files change - Debug Ready: Debug port available on 7777 - Interactive: Press Enter to run tests, r to restart

Exit with Ctrl+C.

Skip Tests

Build without running tests (faster):

cd API_server
mvn clean package -DskipTests

Warning

Only skip tests during development. Always run tests before committing code.

Advanced Build Options

Update Dependencies

Force update of all dependencies:

cd API_server
mvn clean install -U

The -U flag forces Maven to check for updated snapshots.

Offline Build

Build without downloading dependencies:

cd API_server
mvn clean package -o

Requires all dependencies to be in local repository.

Verbose Output

Show detailed build information:

cd API_server
mvn clean package -X

Useful for debugging build issues.

Parallel Builds

Build faster using multiple threads:

cd API_server
mvn clean package -T 4

Uses 4 threads. Adjust based on your CPU cores.

Build Profiles

Development Profile

cd API_server
mvn clean package -Pdev

Production Profile

cd API_server
mvn clean package -Pprod

Note

Profiles are defined in API_server/pom.xml and can customize build behavior.

Liberty Maven Plugin

Start Server

Start OpenLiberty server:

cd API_server
mvn liberty:start

Server runs in background.

Stop Server

Stop the running server:

cd API_server
mvn liberty:stop

Run Server

Start server in foreground:

cd API_server
mvn liberty:run

Exit with Ctrl+C.

Create Server Package

Create a runnable server package:

cd API_server
mvn liberty:package

Output: API_server/target/authentication-test-api.zip

Deploy Application

Deploy WAR to running server:

cd API_server
mvn liberty:deploy

Build Output

Directory Structure

After a successful build:

API_server/target/
├── authentication-test-api.war          # Deployable WAR file
├── authentication-test-api/             # Exploded WAR
├── classes/                             # Compiled classes
├── generated-sources/                   # Generated code
├── maven-archiver/                      # Maven metadata
├── maven-status/                        # Build status
└── test-classes/                        # Compiled test classes

WAR File Contents

The generated WAR file contains:

authentication-test-api.war
├── WEB-INF/
│   ├── classes/                         # Application classes
│   │   └── com/example/api/
│   ├── lib/                             # Dependencies (if any)
│   └── web.xml                          # Web descriptor (optional)
└── META-INF/
    └── MANIFEST.MF                      # Manifest file

Dependency Management

List Dependencies

Show all project dependencies:

cd API_server
mvn dependency:tree

Analyze Dependencies

Check for unused or undeclared dependencies:

cd API_server
mvn dependency:analyze

Download Sources

Download source JARs for dependencies:

cd API_server
mvn dependency:sources

Useful for IDE debugging.

Download Javadocs

Download Javadoc JARs:

cd API_server
mvn dependency:resolve -Dclassifier=javadoc

Testing

Run Specific Test

Run a single test class:

cd API_server
mvn test -Dtest=HelloResourceTest

Run Test Method

Run a specific test method:

cd API_server
mvn test -Dtest=HelloResourceTest#testHelloEndpoint

Skip Tests

Skip test compilation and execution:

cd API_server
mvn package -Dmaven.test.skip=true

Test Coverage

Generate test coverage report (requires jacoco plugin):

cd API_server
mvn clean test jacoco:report

Report: API_server/target/site/jacoco/index.html

Code Quality

Compile with Warnings

Show all compiler warnings:

cd API_server
mvn clean compile -Xlint:all

Format Code

Format code according to style rules (requires formatter plugin):

cd API_server
mvn formatter:format

Troubleshooting

Clear Local Repository

If dependencies are corrupted:

# Remove project dependencies from local repo
rm -rf ~/.m2/repository/com/example/authentication-test-api

# Rebuild
cd API_server
mvn clean install -U

Increase Memory

If build runs out of memory:

export MAVEN_OPTS="-Xmx2048m -XX:MaxPermSize=512m"
cd API_server
mvn clean package

Debug Build

Run Maven in debug mode:

cd API_server
mvn clean package -X > build.log 2>&1

Review build.log for detailed information.

Dependency Conflicts

Resolve dependency conflicts:

cd API_server
mvn dependency:tree -Dverbose

Look for conflicts marked with (omitted for conflict with X.Y.Z).

Build Best Practices

1. Always Clean Before Release

cd API_server
mvn clean package

Ensures no stale artifacts.

2. Run Tests

cd API_server
mvn clean verify

Runs all tests including integration tests.

3. Check for Updates

cd API_server
mvn versions:display-dependency-updates
mvn versions:display-plugin-updates

4. Verify Build Reproducibility

cd API_server
mvn clean package
mvn clean package
diff target/authentication-test-api.war target/authentication-test-api.war

Builds should be identical.

CI/CD Integration

GitHub Actions

- name: Build with Maven
  run: |
    cd API_server
    mvn clean package -B

GitLab CI

build:
  script:
    - cd API_server
    - mvn clean package

Jenkins

sh 'cd API_server && mvn clean package'

Next Steps

• Containerization - Build container images
• Running the Server - Deploy and run the application
• Configuration - Configure the application

Additional Resources

• Maven Documentation
• Liberty Maven Plugin
• Maven Lifecycle Reference