Maven Project Structure

Relevant source files

This document describes the multi-module Maven architecture of PatternFly Java, detailing the POM hierarchy, module organization, dependency management, and packaging strategies. For information about the build process and plugins used, see Build Pipeline. For CI/CD workflows that execute these builds, see CI/CD Workflows.

Overview

PatternFly Java uses a sophisticated multi-module Maven structure with 15 modules organized under a root parent POM. The architecture employs two levels of parent POMs to separate project-wide configuration from code-specific build settings, and uses a BOM (Bill of Materials) to manage dependency versions consistently across all modules.

POM Hierarchy

The project uses a two-tier parent POM structure to separate concerns between project management and code compilation.

Root Parent POM

Module: patternfly-java-parent
Artifact: org.patternfly:patternfly-java-parent
Parent: org.jboss:jboss-parent:52

The root POM pom.xml1-599 inherits from JBoss Parent and defines:

Project metadata (licenses, developers, SCM, issue management)
Version properties for all dependencies and plugins
Module declarations via <modules> pom.xml113-126
Plugin management for tools used across all modules
Common plugin executions (editorconfig, impsort, license, checkstyle, enforcer)
Build profiles (apidoc, quick-build, release, showcase)
Repository declarations for dependency resolution

Key Responsibilities:

Project-wide version coordination
Common quality checks (code style, license headers, import sorting)
Maven enforcer rules (minimum versions, banned repositories)
Profile definitions for special build scenarios

Code Parent POM

Module: patternfly-java-code-parent
Artifact: org.patternfly:patternfly-java-code-parent
Parent: patternfly-java-parent

The code parent POM code-parent/pom.xml1-105 inherits from the root parent and provides:

Dependency management via BOM imports code-parent/pom.xml35-64
Build configuration specific to code modules
Customized license and checkstyle plugin configurations with references to patternfly-java-build-config code-parent/pom.xml70-101

Inheritance Flow:

Sources: pom.xml23-27 code-parent/pom.xml23-28 bom/pom.xml23-28 build-config/pom.xml23-28

Module Organization

PatternFly Java consists of 15 Maven modules organized by functional responsibility.

Module Catalog

Module	Artifact ID	Packaging	Purpose
Configuration & Management
Root	`patternfly-java-parent`	`pom`	Project root, defines all modules
Code Parent	`patternfly-java-code-parent`	`pom`	Parent for code modules
BOM	`patternfly-java-bom`	`pom`	Dependency version management
Build Config	`patternfly-java-build-config`	`jar`	Checkstyle/license resources
Foundation Modules
Core	`patternfly-java-core`	`gwt-lib`	Base classes, utilities, positioning
Tokens	`patternfly-java-tokens`	`gwt-lib`	Generated design tokens
Icons	`patternfly-java-icons`	`gwt-lib`	Generated icon definitions
Component Modules
Layouts	`patternfly-java-layouts`	`gwt-lib`	Grid, Flex, Stack layouts
Components	`patternfly-java-components`	`gwt-lib`	50+ UI components
Charts	`patternfly-java-charts`	`gwt-lib`	Chart component integration
CodeEditor	`patternfly-java-codeeditor`	`gwt-lib`	Monaco editor extension
Finder	`patternfly-java-finder`	`gwt-lib`	Finder pattern extension
Platform Modules
GWT	`patternfly-java-gwt`	`gwt-lib`	GWT aggregation module
J2CL	`patternfly-java-j2cl`	`jar`	J2CL aggregation module
Documentation
Showcase	`patternfly-java-showcase`	`jar`	Demo application (J2CL)

Module Directory Structure

patternfly-java/
 pom.xml                          (root parent)
 code-parent/pom.xml              (code parent)
 bom/pom.xml                      (BOM)
 build-config/                    (build resources)
    src/main/resources/etc/
        license.txt
        checkstyle-suppressions.xml
 core/pom.xml                     (foundation)
 tokens/pom.xml                   (design tokens)
 icons/pom.xml                    (icon definitions)
 layouts/pom.xml                  (layout components)
 components/pom.xml               (UI components)
 charts/pom.xml                   (chart components)
 extensions/
    codeeditor/pom.xml
    finder/pom.xml
 gwt/pom.xml                      (GWT packaging)
 j2cl/pom.xml                     (J2CL packaging)
 showcase/pom.xml                 (demo app)

Sources: pom.xml113-126 README.md107-122

Module Dependencies

Modules depend on each other following a bottom-up architecture where foundation modules are consumed by higher-level modules.

Dependency Graph

Module Dependency Details

Core Dependencies:

patternfly-java-core core/pom.xml39-51 depends only on Elemento (builder API, logger, SVG support)
patternfly-java-tokens depends on Core (not explicitly declared in provided files)
patternfly-java-icons icons/pom.xml35-40 depends on Core
patternfly-java-layouts layouts/pom.xml35-40 depends on Core

Component Dependencies:

patternfly-java-components components/pom.xml35-52 depends on Core, Layouts, Icons, and Tokens
patternfly-java-charts depends on Core (not explicitly shown in provided files)
patternfly-java-codeeditor extensions/codeeditor/pom.xml35-40 depends on Components
patternfly-java-finder extensions/finder/pom.xml35-40 depends on Components

Platform Dependencies:

patternfly-java-gwt gwt/pom.xml47-65 depends on Components and Layouts (with sources), plus GWT user library
patternfly-java-j2cl j2cl/pom.xml35-44 depends on Components and Layouts (no sources needed)

Showcase Dependencies:

patternfly-java-showcase showcase/pom.xml57-104 depends on Components, Layouts, Charts, CodeEditor, J2CL, Elemento router, and J2CL tooling

Sources: core/pom.xml39-63 components/pom.xml35-57 gwt/pom.xml47-70 j2cl/pom.xml35-44 showcase/pom.xml57-104

Packaging Types

PatternFly Java uses three different Maven packaging types depending on the module's purpose and target platform.

Packaging Type Comparison

Packaging	Used By	Build Plugin	Purpose
`pom`	Root, Code Parent, BOM	Standard Maven	Project structure and version management
`gwt-lib`	Core, Tokens, Icons, Layouts, Components, Charts, Extensions, GWT	`gwt-maven-plugin`	GWT-compatible library with module descriptor
`jar`	Build Config, J2CL, Showcase	Standard Maven	Standard Java JAR for J2CL or utilities

GWT Library Packaging

Modules using gwt-lib packaging core/pom.xml31 components/pom.xml31 layouts/pom.xml31 are built with the GWT Maven Plugin pom.xml157-162 and include:

Compiled Java classes in standard JAR structure
Source files (required for GWT/J2CL transpilation)
GWT module descriptor (.gwt.xml file)

GWT Module Configurations:

patternfly-java-core: module name org.patternfly.Core core/pom.xml103-108
patternfly-java-icons: module name org.patternfly.Icons icons/pom.xml96-101
patternfly-java-layouts: module name org.patternfly.Layouts layouts/pom.xml44-50
patternfly-java-components: module name org.patternfly.Components components/pom.xml61-67
patternfly-java-codeeditor: module name org.patternfly.extension.CodeEditor extensions/codeeditor/pom.xml45-50
patternfly-java-finder: module name org.patternfly.extension.Finder extensions/finder/pom.xml45-50
patternfly-java-gwt: module name org.patternfly.PatternFly gwt/pom.xml74-80

Standard JAR Packaging

The patternfly-java-j2cl module j2cl/pom.xml31 uses standard JAR packaging but includes special resource handling to bundle JavaScript files j2cl/pom.xml46-60:

This ensures JavaScript interop files and externs are included in the JAR for J2CL compilation.

Sources: core/pom.xml31 components/pom.xml31 j2cl/pom.xml31 j2cl/pom.xml46-60

Bill of Materials (BOM)

The BOM module provides centralized dependency version management for all PatternFly Java artifacts.

BOM Structure

Module: patternfly-java-bom
Artifact: org.patternfly:patternfly-java-bom
Parent: org.jboss:jboss-parent:51 (independent from main parent)

The BOM bom/pom.xml1-256 declares all PatternFly Java modules in <dependencyManagement> bom/pom.xml83-201 without specifying <scope> or <optional> tags, following Maven BOM best practices.

Declared Artifacts

For each module, the BOM declares both the primary artifact and sources classifier:

This pattern is repeated for all modules: core, tokens, icons, layouts, components, charts, codeeditor, finder, gwt, and j2cl bom/pom.xml96-199

BOM Usage

Consumer projects import the BOM in their <dependencyManagement> section README.md42-54:

Then declare dependencies without version tags README.md58-73:

BOM Release Profile

The BOM has its own release profile bom/pom.xml215-254 that mirrors the root POM's release configuration, enabling GPG signing and Central Publishing Plugin deployment.

Sources: bom/pom.xml1-256 bom/pom.xml83-201 README.md42-73

Build Configuration Module

The patternfly-java-build-config module provides shared build resources for code quality checks.

Module Purpose

Module: patternfly-java-build-config
Artifact: org.patternfly:patternfly-java-build-config
Packaging: jar

This module build-config/pom.xml1-53 packages configuration files as resources that can be referenced by other modules via classpath lookup.

Packaged Resources

Located in src/main/resources/etc/:

license.txt: Apache 2.0 license header template
checkstyle-suppressions.xml: Checkstyle rule suppressions

Usage in Code Parent

The code-parent POM declares patternfly-java-build-config as a dependency for both the license plugin code-parent/pom.xml80-86 and checkstyle plugin code-parent/pom.xml94-100:

This allows all code modules inheriting from code-parent to reference etc/license.txt and etc/checkstyle-suppressions.xml from the build-config JAR's classpath.

Sources: build-config/pom.xml1-53 code-parent/pom.xml70-101

Module Activation and Profiles

Not all modules build by default. Some are activated only via Maven profiles.

Default Build Modules

The root POM's default <modules> section pom.xml113-126 includes:

This builds the core library modules but excludes optional modules.

Profile-Activated Modules

API Documentation Profile (-P apidoc) pom.xml458-463:

Activates the apidoc module for generating aggregated Javadoc
Used during releases and manual documentation builds

Showcase Profile (-P showcase) pom.xml557-562:

Activates the showcase module
Used for building and deploying the demo application
Often combined with prod profile for production builds

Quick Build Profile (-P quick-build or -Dquickly) pom.xml465-481:

Skips quality checks: checkstyle, editorconfig, enforcer, impsort, license, javadoc
Skips tests and integration tests
Used for rapid local development iterations

Release Profile (-P release) pom.xml483-556:

Enforces no SNAPSHOT dependencies pom.xml491-496
Attaches sources JAR pom.xml498-509
Attaches Javadoc JAR pom.xml510-521
Signs artifacts with GPG pom.xml522-541
Configures Central Publishing Maven Plugin pom.xml542-553 for automated deployment

Profile Usage Examples

Sources: pom.xml113-126 pom.xml457-563

Dependency Management Strategy

PatternFly Java uses a multi-layered dependency management approach.

Layer 1: Root POM Properties

The root POM pom.xml78-111 defines version properties for:

External dependencies: Elemento, GWT, Elemental2, JUnit, Node.js, PatternFly
Build plugins: Central Publishing, Frontend, GWT, J2CL, Checkstyle, Javadoc, License
Build settings: Java version, encoding

Layer 2: BOM Import

The code-parent POM code-parent/pom.xml35-64 imports two BOMs:

Layer 3: Module Dependencies

Individual modules declare dependencies without versions:

Example from patternfly-java-components components/pom.xml35-52:

Versions are resolved from the imported BOMs, ensuring consistency across all modules.

Sources: pom.xml78-111 code-parent/pom.xml35-64 components/pom.xml35-57

Version Synchronization

All PatternFly Java modules share a single version number managed in three places.

Version Declarations

Root POM pom.xml31:

Code Parent code-parent/pom.xml26:

BOM bom/pom.xml32:

All other modules inherit their version from the code-parent via the <parent> section and use ${project.version} when referencing other PatternFly modules.

Version Update Process

Version updates must be coordinated across:

Root POM pom.xml31
Code Parent POM code-parent/pom.xml26
BOM POM bom/pom.xml32
CHANGELOG.md CHANGELOG.md1-762 for release notes

The project follows Semantic Versioning, as documented in CHANGELOG.md5

Sources: pom.xml31 code-parent/pom.xml26 bom/pom.xml32 CHANGELOG.md5

Plugin Configuration Inheritance

Build plugins are configured at the root level and inherited by all modules with module-specific overrides where necessary.

Root-Level Plugin Management

The root POM defines plugin versions in <pluginManagement> pom.xml132-290 for:

depgraph-maven-plugin: Dependency graph visualization pom.xml135-139
editorconfig-maven-plugin: Code formatting checks pom.xml140-151
frontend-maven-plugin: Node.js/npm integration pom.xml152-156
gwt-maven-plugin: GWT compilation pom.xml157-162
impsort-maven-plugin: Import statement sorting pom.xml163-172
jbang-maven-plugin: JBang script execution pom.xml173-177
j2cl-maven-plugin: J2CL compilation pom.xml178-186
keepachangelog-maven-plugin: Changelog parsing pom.xml187-191
license-maven-plugin: License header management pom.xml192-234
maven-checkstyle-plugin: Code style enforcement pom.xml235-253
maven-enforcer-plugin: Build environment validation pom.xml254-285
maven-javadoc-plugin: API documentation pom.xml286-289

Root-Level Plugin Executions

Common plugins execute for all modules pom.xml293-454:

Build Helper pom.xml295-312:

Adds src/demo/java as test source directory for demo code

Dependency Graph pom.xml313-341:

Generates visual dependency graph
Configured to show only PatternFly and key external dependencies

Editorconfig pom.xml342-361:

Formats files in process-sources phase
Validates formatting in verify phase

Import Sort pom.xml362-381:

Sorts imports in process-sources phase
Validates import order in verify phase

License Check pom.xml382-401:

Formats license headers in process-sources phase
Validates headers in verify phase

Checkstyle pom.xml402-414:

Validates code style in verify phase

Enforcer pom.xml415-427:

Validates Maven and Java versions in initialize phase

Javadoc pom.xml428-453:

Configured with links to Elemento, GWT, and Elemental2 documentation
Configured to use demo code snippets with --snippet-path pom.xml432

Module-Specific Plugin Configurations

Individual modules override or extend plugin configurations:

Core Module core/pom.xml81-101:

Adds JBang execution to generate Version.java core/pom.xml82-101

Icons Module icons/pom.xml59-94:

Uses Frontend plugin to run npm scripts for icon generation icons/pom.xml60-93

Showcase Module showcase/pom.xml126-200:

Uses JBang to generate showcase code showcase/pom.xml126-157
Uses Frontend plugin for Node.js and npm showcase/pom.xml166-200
Uses J2CL plugin for Java-to-JavaScript compilation showcase/pom.xml201-218

Sources: pom.xml132-454 core/pom.xml81-101 icons/pom.xml59-94 showcase/pom.xml106-220

Repository Configuration

The project declares custom Maven repositories for dependency resolution.

Snapshot Repository

Configured for SNAPSHOT dependencies pom.xml565-576:

JBoss Nexus Repository

Configured for JBoss releases pom.xml576-586:

Plugin Repository

Configured for JBoss plugin releases pom.xml587-598:

Distribution Management

SNAPSHOT artifacts are deployed to Maven Central's snapshot repository pom.xml71-76:

Release artifacts are deployed via the Central Publishing Maven Plugin configured in the release profile pom.xml542-553

Sources: pom.xml71-76 pom.xml565-598