21CTO

Jun 17, 2026 · Fundamentals

Project Valhalla Hits JDK 28: Preview of Value Types Arrives

Project Valhalla's JEP 401, introducing value classes and objects, merges into the OpenJDK mainline as a preview feature in JDK 28, involving 1,816 files and over 197,000 new lines, with a cautious rollout timeline and notable design trade‑offs for Java performance.