Java 27 grows up, makes better choices

Java version 27, set for release Tuesday, marks a step in the language's maturity with better default settings. Backend engineer Arvind Kumar noted on his Codefarm site that "JDK 27 is the release where Java stops asking you to opt in to good defaults and simply turns them on." These easier settings reduce the burden on developers, who no longer have to make changes to their code.

In addition, JDK 27 brings four new features ready for production use. Unlike many other releases, these enhancements don't require immediate code modifications. The release also includes five other features in preview mode for further development. One notable improvement is the default compact headers for Java objects, which reduce memory usage.

With a 64-bit header instead of the traditional 96-bit header, Java 27 can save considerable memory, resulting in 22% less heap space and 8% less CPU time in SPECjbb2015 Java benchmark tests. Amazon and SAP have already adopted these compact headers in their production systems. Java's development team is also preparing for the future by implementing post-quantum cryptography measures, adding hybrid key exchange options to defend against potential quantum computing attacks.

The language's garbage collection has also been updated, replacing the Serial GC with the more efficient Garbage-First (G1) GC as the default. This change eliminates the need for explicit command-line flags in many containerized applications, leading to better performance and telemetry data collection. The upcoming Java 28 will bring additional enhancements, including a simple JSON API and a revised Shenandoah garbage collector.