New Features in Java 16: A Comprehensive Overview

When developers were still deep in Java 8, the next version, Java 16, was announced with a short‑term support schedule similar to Java 15, offering only six months of Oracle support.

According to the release plan, JDK 16 entered the ramp‑down phase on December 10, 2020, the release‑candidate phase from February 4‑18, 2021, and the final GA release is expected on March 16, 2021.

The upcoming JDK 16 brings many new features:

Sealed classes and interfaces, previewed in JDK 15, allow authors to restrict which other classes or interfaces may extend or implement them, providing a more declarative way to control subclassing and laying groundwork for pattern matching.

Strong encapsulation of JDK internals by default, with the exception of critical internal APIs such as sun.misc.Unsafe . This aims to improve security and maintainability while encouraging migration to standard APIs.

A foreign‑memory access API (incubator) that gives Java programs safe access to memory outside the Java heap, targeting use cases like external storage, native, persistent, and managed heap memory.

Improvements to the Z Garbage Collector (ZGC) by moving thread‑stack processing from safepoints to the concurrent phase, removing that work from ZGC safepoints.

Elastic metaspace enhancements that return unused class metadata memory to the operating system more quickly, reducing metaspace footprint and simplifying maintenance.

Enablement of C++14 language features in the JDK’s C++ source code, with guidance on which features are available for HotSpot VM code.

An incubating Vector API that provides a module for expressing vector computations mapped to the best hardware instructions on supported CPU architectures, delivering higher performance than equivalent scalar code.

Porting of the JDK to the Windows/AArch64 platform, reflecting the growing importance of ARM64 hardware in servers and consumer devices.

Porting of the JDK to Alpine Linux and other musl‑based Linux distributions on x64 and AArch64, catering to cloud, microservice, and container environments where small image sizes are valuable.

Record classes that serve as transparent carriers for immutable data.

Support for Unix‑domain socket channels (AF_UNIX) added to the java.nio.channels package, extending the channel hierarchy to enable inter‑process communication via file‑system path names on Unix and Windows platforms.

Pattern matching for the instanceof operator, allowing more concise and safer extraction of components from objects.

The jpackage tool, moving from an incubator in JDK 14/15 to a production‑ready utility in JDK 16, enables packaging of standalone Java applications for native installers (MSI, EXE, PKG, DMG, DEB, RPM).

Migration of the OpenJDK source repository from Mercurial to Git, leveraging modern version‑control tooling and hosting.

Migration of the JDK hosting platform to GitHub (JEP 369), with the transition completed in September 2020.

After Java 16, Java 17 is slated for release in September 2021 as a long‑term support (LTS) version, giving developers on the front line more time to adopt the new features.

Reference link: https://www.infoworld.com/article/3569150/jdk-16-the-new-features-in-java-16.html