Development Environment

Relevant source files

This page provides an orientation to the development environment for patternfly-java contributors and library developers. It covers the required toolchain, how the modules are built together, and how the showcase application is run locally. For detailed step-by-step setup instructions, see Local Development Setup. For the showcase-specific workflow, see Showcase Application Development. For a comparison of the two compilation targets, see GWT vs J2CL.

Toolchain Requirements

The project requires three tools installed on the host machine. Node.js is provisioned automatically by frontend-maven-plugin for modules that need it; you do not need to install Node.js manually for most tasks.

Tool	Minimum Version	Configuration Source
JDK	21	`<java.version>21</java.version>` in pom.xml106
Apache Maven	3.9.9	`<maven.min.version>3.9.9</maven.min.version>` in pom.xml108
Node.js	v24.10.0	`<version.node>v24.10.0</version.node>` in pom.xml87

The maven-enforcer-plugin validates the Java and Maven version constraints at build initialization time (initialize phase) and fails the build if they are not met. See pom.xml257-285

Module Overview

The repository is a Maven multi-module project. The top-level pom.xml lists all library modules as direct children. The showcase module is gated behind the -P showcase Maven profile and is not built by default.

Standard module build (default profile)

mvn install

Full build including showcase

mvn install -P showcase

Quick build (skip checks and tests)

mvn install -Dquickly

The -Dquickly property activates the quick-build profile pom.xml465-481 which disables checkstyle, editorconfig, import sorting, license checks, Javadoc generation, and all tests.

Sources: pom.xml113-126 pom.xml457-481 pom.xml557-562

Module Build Map

The following diagram maps each Maven module to its artifact ID and source directory, showing the module boundaries that developers work within.

Maven module source directory mapping

Sources: pom.xml113-126 pom.xml557-562 core/pom.xml30-32 j2cl/pom.xml30-33 gwt/pom.xml30-33 showcase/pom.xml24-28

Two Compilation Targets

patternfly-java produces output for two distinct Java-to-JavaScript compilation toolchains. Each has its own Maven module that acts as the consumer-facing dependency.

Aspect	GWT	J2CL
Maven artifact	`patternfly-java-gwt`	`patternfly-java-j2cl`
Packaging	`gwt-lib`	`jar`
Module POM	gwt/pom.xml	j2cl/pom.xml
GWT module descriptor	`org.patternfly.PatternFly`
Used by showcase	No (removed in 0.3.0)	Yes
Popper.js injection	`ScriptInjector` (GWT API)	Bundled JS resource

Both modules depend on patternfly-java-components and patternfly-java-layouts. The GWT module additionally depends on gwt-user. See GWT vs J2CL for a detailed comparison.

Sources: gwt/pom.xml47-70 j2cl/pom.xml35-44

Development Workflows

There are two distinct development workflows depending on what is being changed.

Library module development workflow

Showcase application development workflow

In development mode, two processes must run concurrently:

mvn j2cl:watch -P showcase starts J2CL incremental compilation in watch mode; wait for Build Complete: ready for browser refresh before proceeding.
cd showcase && npm run watch starts the Parcel bundler and the Express dev server at http://localhost:1234.

Sources: showcase/README.md7-30 showcase/server.js1-63 showcase/pom.xml202-218

Showcase Request Routing

The Express server in showcase/server.js routes requests to the appropriate backend based on URL pattern.

showcase/server.js routing logic

Sources: showcase/server.js24-58

Production Build

For a production build with full Closure compiler optimizations applied by J2CL:

mvn clean package -P showcase,prod

The prod profile showcase/pom.xml222-250 switches the J2CL compilation level from BUNDLE_JAR to ADVANCED_OPTIMIZATIONS and disables incremental builds. It also invokes npm run prod via frontend-maven-plugin to run Parcel in production mode.

To serve the production build locally after it completes:

cd showcase
mvn com.github.eirslett:frontend-maven-plugin:npm@http-server

Then open https://localhost:8080.

Sources: showcase/README.md33-43 showcase/pom.xml222-250

Key Build Commands Reference

Goal	Command
Build all library modules	`mvn install`
Build all modules, skip checks/tests	`mvn install -Dquickly`
Build showcase (dev mode, J2CL watch)	`mvn j2cl:watch -P showcase`
Start Parcel + dev server for showcase	`cd showcase && npm run watch`
Build showcase for production	`mvn clean package -P showcase,prod`
Serve production showcase build	`cd showcase && mvn com.github.eirslett:frontend-maven-plugin:npm@http-server`
Generate aggregate Javadoc	`mvn package -P apidoc`

Sources: pom.xml457-562 showcase/README.md1-43 showcase/pom.xml222-250

Local Development Setup (3.1) prerequisites, cloning, and building step by step.
Showcase Application Development (3.2) detailed explanation of the two-process dev workflow, Parcel proxy configuration, and SPA routing.
GWT vs J2CL (3.3) comparison of the two compilation targets, platform module differences, and guidance for new projects.
Build Pipeline (2.3) the end-to-end Maven lifecycle, code generation steps, and plugin integration.