Java 15 features | What's new in Java 15?

Java 15 Features

JDK 15 is the open-source reference implementation of version 15 of the Java SE Platform as specified by by JSR 390 in the Java Community Process.

Some of the important Java 15 features are:

• 371: Hidden Classes
• 372: Remove the Nashorn JavaScript Engine
• 377: ZGC: A Scalable Low-Latency Garbage Collector
• 378: Text Blocks
• 379: Shenandoah: A Low-Pause-Time Garbage Collector
• 373: Reimplement the Legacy DatagramSocket API
• 374: Disable and Deprecate Biased Locking
• 375: Pattern Matching for instanceof
• 339: Edwards-Curve Digital Signature Algorithm (EdDSA)
• 360: Sealed Classes (Preview)
• 381: Remove the Solaris and SPARC Ports
• 383: Foreign-Memory Access API (Second Incubator)
• 384: Records (Second Preview)

Some More java 15 features are coming up. We will discuss once openjdk Java Community Process released some information.

Java 15 Features :

Hidden Classes

Hidden classes are classes that cannot be used directly by the bytecode of other classes. Hidden classes are intended for use by frameworks that generate classes at run time and use them indirectly, via reflection. A hidden class may be defined as a member of an access control nest, and may be unloaded independently of other classes.

Read more about Hidden classes https://theprogrammersfirst.blogspot.com/2020/04/java-hidden-classes.html

Text Blocks

A text block is a multi-line string literal that avoids the need for most escape sequences, automatically formats the string in a predictable way, and gives the developer control over the format when desired.

Read more about Text Blocks https://theprogrammersfirst.blogspot.com/2020/02/java-13-text-blocks.html

Reimplement the Legacy DatagramSocket API

Currently, the DatagramSocket and MulticastSocket classes delegate all socket calls to a java.net.DatagramSocketImpl implementation, for which different platform-specific concrete implementations exist: PlainDatagramSocketImpl on Unix platforms, and TwoStackPlainDatagramSocketImpl and DualPlainDatagramSocketImpl on Windows platforms.

In JEP 353 for SocketImpl, this JEP proposes to make DatagramSocket internally wrap another instance of DatagramSocket to which it delegates all calls directly. The wrapped instance is either a socket adapter created from a NIO DatagramChannel::socket (the new implementation), or else a clone of the legacy DatagramSocket class which then delegates to the legacy DatagramSocketImpl implementation (for the purpose of implementing a backward compatibility switch).

The new implementation is enabled by default. It provides non-interruptible behavior for datagram and multicast sockets by directly using the platform-default implementation of the selector provider (sun.nio.ch.SelectorProviderImpl and sun.nio.ch.DatagramChannelImpl). Installing a custom selector provider will thus have no effect on DatagramSocket and MulticastSocket.

Java - Pattern Matching for instanceof 

Enhance the Java programming language with pattern matching for the instanceof operator. Pattern matching allows common logic in a program, namely the conditional extraction of components from objects, to be expressed more concisely and safely.

Read more about pattern matching for the instanceof operator https://theprogrammersfirst.blogspot.com/2020/05/java-pattern-matching-for-instanceof.html

Java 15 Features : JDK 15 release Schedule

2020/08/06 - Initial Release Candidate
2020/08/20 - Final Release Candidate
2020/09/15 - General Availability