Java Development Kit 15 in Java 15

Posted on by wm-admin
Java 15 - JDK 15

Overview

Java Development Kit 15, Oracle releasing the next version of Java SE. With the new feature set, they reached their second slow downtime in mid-July. But the available Stabilization repository to select bug fixes. Although, Java 15 provides some interesting new functionality, preview features, and JDK incubator capabilities

Java 15 release date: Java 15 also expects to be launch in September 2020.

Listed below main new open JDK features:

  • Hidden Classes: Hidden classes are classes that other classes bytecode can not use explicitly. Hidden classes aim to use frameworks that generate classes at runtime and use them indirectly through reflection. 
  • Foreign memory access API: The second incubator of a foreign memory access API, which would also allow Java programs to access foreign memory outside the Java heap safely and efficiently.
  • Preview of Sealed Class: This function includes allowing the class or interface author to monitor which code is responsible for its implementation. Additionally, provide a more declarative way to limit the use of a superclass than control modifiers. And endorse future pattern-matching directions by underpinning the rigorous pattern analysis.
  • A Scalable Low-Latency Garbage Collector: JDK 11 introduced the Z Garbage Collector as an experimental tool. For Java 15, it appears the time might have also come for ZGC to become a feature of development.

Some More Points

  • Removal of Solaris: Support for Solaris on SPARC and x64 and Linux on SPARC is removed.
  • Deprecate RMI Activation for Removal: The activation of RMI will be discontinued, this won’t affect other RMI pieces.
  • Text Blocks: JDK 13 introduced the Text Block as the Preview function in mid-2019, which was then revisited as Second Preview by adding two new escape sequences in Java 14. Moreover, JDK 14 feedback suggests that the Text Blocks feature is now ready to become a regular feature in Java 15 as permanent and final.
  • Shenandoah: A Low-Pause-Time Garbage Collector: Shenandoah was placed into JDK 12-JEP 189 as an Experimental tool. In addition, now in Java 15, Shenandoah is ready as a production tool.
  • Records: For a second preview edition for JDK 15, records that are groups of permanent data that act as transparent carriers will be also included after debuting as an early preview in JDK 14.
  • Remove the Nashorn JavaScript Engine: Drop the Nashorn JavaScript script generator, the APIs, and also the js framework as already deplored in Java 11.
    • Jdk.scripting.nashorn: includes the packages jdk.nashorn.api.scripting and jdk.nashorn.api.tree
    • Jdk.scripting.nashorn: includes the packages jdk.nashorn.api.scripting and jdk.nashorn.api.tree

Java Development Kit 15 improves more essential features:

  1. Concurrent class unloading
  2. Maximum heap size up from 4 TB to 16 TB
  3. Minimum heap size went down to 8 MB
  4. -XX: SoftMaxHeapSize
  5. JFR leak profiler support
  6. Class-data sharing support
  7. Address spaces are small and discrete
  8. Support for placing the heap on NVRAM
  9. Improved NUMA awareness
  10. Multi-threaded heap pre-touching
  11. Pattern Matching for instanceof
  12. Disable and Deprecate Biased Locking
  13. Rebuild the Legacy DatagramSocket API

Bottom line

However, with many of Java’s features backed by big names, it is possible to expect many of these preview and incubatory features to become solidified full features before Java 17.

Related posts