Java's Biggest Language Change in a Decade Is Finally Landing - It Took 197,000 Lines of Code
The Next Web, Monday, June 15th, 2026
Oracle is integrating JEP 401 value classes into Java's JDK 28, a 197,000-line change addressing fundamental performance limits.
Oracle engineer Lois Foltan confirmed that JEP 401, introducing value classes, will integrate into OpenJDK mainline targeting JDK 28.
The change spans 1,816 files and is so large that other committers must pause major work during integration.
Value classes eliminate object identity by distinguishing objects solely through field values rather than memory location, letting the JVM optimize storage and improve performance.
Project Valhalla, begun in 2014, aims to gradually migrate existing JDK classes like Integer to value-based implementations. The feature arrives as a preview in JDK 28 (March 2027).