Java 27 Released

The default garbage collector is now G1, which can significantly impact application performance and memory usage.

Oracle has announced the General Availability of Java 27 (JDK 27), signaling the release of the latest version of the Java Development Kit. This update includes nine JDK Enhancement Proposals (JEPs), featuring significant changes such as making the G1 garbage collector the default across all environments and introducing post-quantum hybrid key exchange for TLS 1.3. Additionally, it brings previews for features like Lazy Constants, Primitive Types in Patterns, and Structured Concurrency, alongside Compact Object Headers being enabled by default. The release also incorporates advancements in the Vector API and PEM encodings for cryptographic objects. This release follows the shipment of build 35 as the second Release Candidate on August 20th, with no reported P1 bugs since then, marking build 35 as the production-ready GA build.

Java 27's release signifies a continued focus on performance and security enhancements within the Java ecosystem. The default adoption of the G1 garbage collector aims to optimize memory management and reduce latency for a broad range of applications, potentially affecting developers who previously relied on other collectors or custom tuning. Furthermore, the inclusion of post-quantum cryptography in TLS 1.3 is a forward-looking move to protect against future cryptographic threats, underscoring the platform's commitment to evolving security standards.

The extensive preview features, such as Primitive Types in Patterns and Structured Concurrency, suggest that developers can anticipate more streamlined and robust code structures in upcoming Java versions. While these are not yet finalized, their inclusion indicates a clear direction for language evolution, encouraging early adoption and feedback from the community. This release also emphasizes developer experience with features like Compact Object Headers by default, which can lead to more memory-efficient JVMs and improved application footprints.