This article explains Java hidden classes—runtime‑generated, reflection‑only classes—through a clear example that creates a simple class, encodes it, loads it as a hidden class, and invokes its method, demonstrating a powerful dynamic feature for frameworks.
Java 15, released in September 2020, brings fourteen major enhancements—including EdDSA signatures, hidden classes, reimplemented networking APIs, production‑grade ZGC and Shenandoah GCs, permanent text blocks, sealed classes, pattern‑matching instanceof, records, and foreign memory access—while showcasing significant contributions from Chinese tech firms to the OpenJDK community.
Oracle’s Jim Laskey proposes JEP 372 to drop the Nashorn JavaScript engine and its APIs from the JDK, detailing the modules to be removed, the impact on javax.script, and community reactions including a shift toward GraalVM.
