Java Development Kit 27, an Oracle-driven, planned update to standard Java, is set to reach its initial release candidate (RC) stage on August 6. This update has features ranging from making the Garbage-First (G1) garbage collector the default collector and adding structured concurrency to simplify concurrent programming. JDK 27 is currently in rampdown phase 2, with the feature set now frozen.
Overall, there are nine features listed on what is described as a reference implementation of JDK 27. The first five features include making G1 the default garbage collector, post-quantum hybrid key exchange for TLS 1.3, lazy constants, structured concurrency, and primitive types in patterns, instanceof, and switch. The next four include compact object headers, JFR (JDK Flight Recorder) in-process data redaction, a vector API, and PEM (Privacy-Enhanced Mail) encodings for cryptographic objects.
The final release candidate stage for JDK 27 follows on August 20, with general availability scheduled for September 15. Early-access builds for JDK 27 can be found at jdk.java.net.
With JDK 27, G1 becomes the default garbage collector in all environments, rather than just in server environments. Goals are to ensure that the HotSpot JVM will always select G1 and that performance including throughput, latency, memory footprint, and startup time does not degrade significantly.
