News

Java 23 Release Candidate Introduces Key Previews, Drops String Templates

• By John K. Waters
• September 3, 2024

Java Development Kit (JDK) 23 has reached the release candidate stage, marking its next step toward general availability on September 17, 2024. The upcoming non-LTS (Long Term Support) release, with only six months of official support from Oracle, finalizes a dozen new features designed to enhance Java’s functionality.

JDK 23 includes previews of scoped values, structured concurrency, and module import declarations. However, a proposed third preview of string templates, featured in JDK 21 and JDK 22, has been removed. The OpenJDK community decided the feature required further evaluation before it could be finalized in a future release.

This release brings continued improvements to performance, particularly through such enhancements the Z Garbage Collector’s (ZGC) new default generational mode, designed to boost efficiency by focusing on collecting short-lived objects. The release also introduces a second preview of stream gatherers, designed to provide custom operations for the stream API, and a new class-file API for developers working with the Java Virtual Machine.

Oracle’s ongoing focus on improving concurrency is highlighted with the third preview of structured concurrency, aiming to simplify parallel task management. JDK 23 also previews flexible constructor bodies and implicitly declared classes and methods, allowing for easier programming for newcomers and experienced developers alike.

Although JDK 23 will not feature long-term support, it continues to pave the way for future innovations in the Java ecosystem. Developers can access early builds of JDK 23 at jdk.java.net.