This projects requires Java 8, to maximize compatibility.

We require Java 11 for building the project, while the artifacts published are compatible with Java 8.

Take a look at the Documentation.

While new features are being added, and the project is evolving, the core features are solidly implemented. The library is mature and used in production.

The project is actively maintained. Feel free to open issues to ask any question, help, or support.

For visibility on the future plans regarding this project refer to the Roadmap.

Currently the project is on-par with the LionWeb specifications.

In particular, this library supports both version 2023.1 and 2024.1 of the specs.

dependencies {
   implementation("io.lionweb.lionweb-java:lionweb-java-2024.1-core:$lionwebVersion")
}

Before opening in IDEA run:

./gradlew setup

This will generate necessary classes.

Contains LionCore (M2) and LionWeb (M1) implementations in Java, including (de-)serializers from/to JSON.

Contains im/exporters to convert models between LionCore ↔ Ecore and LionWeb ↔ EMF.

Some of LionCore's built-in elements have no direct representation in Ecore. This sub-project is an Eclipse project that defines an EPackage builtins to host the equivalent elements in Ecore. The language's nsURI is http://lionweb.io/lionweb-java/emf/core/builtins/2023.1.

Functionalities to connect to the LionWeb Server. It also includes an in-memory server, paired with a Client exposing the same interface as the interface for connecting to the LionWeb Server.

Facilities to write functional tests against the LionWeb Server.

The Changelog is here.

To ensure proper testing coverage we configured Jacoco. You can run ./gradlew jacocoTestReport and then find the report for each module, under build/reports/jacoco.

The project includes JMH (Java Microbenchmark Harness) benchmarks to measure and optimize serialization/deserialization performance:

• DeserializeFromChunkBenchmark - Benchmarks deserializeSerializationChunk performance, measuring both the core deserialization logic (excluding JSON parsing) and end-to-end deserialization from JSON
• SerializeNodesToChunkBenchmark - Benchmarks serializeNodesToSerializationChunk performance, comparing direct serialization of flat node collections versus tree-based serialization with traversal

These benchmarks use GC profiling to track memory allocations and identify optimization opportunities. They are located in core/src/performanceTest/java and can be run using:

./gradlew :core:performanceTest

Or run directly from your IDE by executing the main method in each benchmark class.

This project is part of the LionWeb initiative.

The project is currently maintained by Federico Tomassetti with contributions from:

• Ulyana Tikhonova
• Meinte Boersma
• Niko Stotz
• Tiago Baptista

Contributions include support in the design, code contributions, code reviews, and bug reports.