Java 25, the Next LTS Release, Delivers Finalized Features and Focus on Performance and Runtime

"Nine of these features are focused on performance and runtime. Seven of these, Scoped Values, Key Derivation Function API, Module Import Declarations, Compact Source Files and Instance Main Methods, Flexible Constructor Bodies, Compact Object Headers and Generational Shenandoh, are finalized after having evolved from their respective incubations and previews with the exception of the latter two that were experimental features in JDK 24."

"This release also provides a focus on performance and runtime as nine of these JEPs are under the auspices of Project Leyden and the HotSpot JVM. This includes two JEPs, Ahead-of-Time Command-Line Ergonomics and Ahead-of-Time Method Profiling, that join JEP 483, Ahead-of-Time Class Loading & Linking, the first feature delivered by Project Leyden in JDK 24. Shown in the graph below, as presented in this Oracle blog post, are the number of JEPs in each Java release since JDK 8."

"JFR Method Timing & Tracing JEP 520, JFR Method Timing & Tracing, proposes to extend the JFR with facilities for method timing and tracing via the bytecode interface. Two new JFR events, jdk.MethodTiming and jdk.MethodTrace, used in the and classes, respectively, accept a filter to select the appropriate methods for timing and tracing. Compact Object Headers JEP 519, Compact Object Headers, proposes to promote this feature from experimental to product. Inspired by Project Lilliput, this feature " reduces the size of object headers in the HotSpot JVM from between 96 and 128 bits down to 64 bits on 64-bit architectures." More details on JEP 519 may be found in this InfoQ ne"

Oracle released Java 25 as the first long-term support (LTS) release since JDK 21. The final feature set contains 18 JEPs, seven finalized and nine focused on performance and runtime. Seven features — Scoped Values; Key Derivation Function API; Module Import Declarations; Compact Source Files and Instance Main Methods; Flexible Constructor Bodies; Compact Object Headers; and Generational Shenandoh — graduated from incubations or previews, while Compact Object Headers and Generational Shenandoh were experimental in JDK 24. Nine JEPs are under Project Leyden and HotSpot, including Ahead-of-Time Command-Line Ergonomics and Ahead-of-Time Method Profiling alongside JEP 483. JEP 520 adds JFR method timing and tracing events and JEP 519 reduces HotSpot object header sizes to 64 bits on 64-bit architectures.

Read at InfoQ