Open-Core with Core Java and Vaadin — Part 2

Sat, 23 May 2026 11:33:42 +0000

Editions, runtime, and quality assurance.

All source code presented here is published on GitHub and available at https://3g3.eu/naityh.

Recap of part one

The first part of this article developed the abstract mechanics of the open-core application. From two independent Maven projects with strictly asymmetric dependency direction, a deliberately slim extension API with the contribution types RouteContribution, MenuContribution, NavbarContribution, and CounterEventListener, a FeatureRegistry that discovers its contributions via the Java standard library’s ServiceLoader, and a Vaadin integration consisting of MainLayout and OpenCoreRouteInitializer, an apparatus is now in place that can accept arbitrary contributions in ordered form, without the core needing to know their identity.

Open-Core with Core Java and Vaadin — Part 1

Fri, 22 May 2026 11:33:04 +0000

Architecture, extension API, and Vaadin integration.

1. Introduction and motivation

The open-core model is often reduced in discussion to questions of licensing or commercial positioning. An open-source variant of a piece of software is complemented by a commercially distributed variant that brings additional features. Anyone who actually wants to implement such a separation in an existing codebase quickly discovers that the real difficulty lies neither in the licence text nor in the choice of repository, but in the code’s architecture.

Sven Ruppert on JAVAPRO International

Open-Core with Core Java and Vaadin — Part 2

Recap of part one

Open-Core with Core Java and Vaadin — Part 1

1. Introduction and motivation