Jenesis

Introduction

Jenesis is a build tool for Java, written in Java. A build is an ordinary Java program - you configure it by writing code against a small API, not by learning a new markup language, and you run it with the JDK you already have. There is no plugin ecosystem to install: a build is composed from steps that are just objects you can read, extend, and test.

This section also covers jpx, a companion command that resolves and runs a published module's main class the way npx runs a package - it ships in the same distribution.

Why another build tool

Two convictions shape everything here:

  • Configuration is code. A build is expressed in Project.java, a normal Java file the JDK launches directly. You get types, an IDE, and refactoring for your build the same as for your application.
  • The module system is a feature, not a footnote. module-info.java drives the build: Jenesis reads your declared modules, resolves the module path, and carries a real module graph all the way through to packaging - instead of flattening it into a class path and hoping.
New to Jenesis? Read this page, then Getting started to install it and run your first build. Every later chapter assumes only what came before it. Prefer to learn by example? Every feature has a runnable project in Demos.

What's in this section

The chapters build up from zero knowledge:

  1. Introduction - you are here.
  2. Getting started - install via SDKMAN, build an example, and read the Project.java model.
  3. Core concepts - build steps, the build graph, layouts, and the module-system specifics.
  4. Configuration - jenesis.properties, per-module configuration, and profiles.
  5. Building & running - compile, annotation processing, test, Execute, and watch mode.
  6. Dependencies - resolution, strict pinning, module-name lookup, and exclusions.
  7. Code quality & testing - formatting, coverage, test selection, and mutation testing.
  8. Other JVM languages - Kotlin, Scala, and Groovy.
  9. Supply-chain features - SBOM, dependency licensing, and vulnerability scanning.
  10. Packaging & distribution - executables, bundles, jlink/jpackage, native images, launcher jars.
  11. Build performance & isolation - Docker isolation and the build cache.
  12. Extending the build - custom assemblers and build definitions.
  13. jpx - running a published module's main class.
  14. Reference - the command line, configuration keys, and the built-in steps.
  15. Demos - a runnable example project for every feature (already available).