The Java Development Kit 20: What’s next?

Published on Sep 27, 2022

In the next version of Java, features such as universal generics, primitive types, and virtual threads could be included.

On September 20, Java 19 was released, and Java 20 will follow in March 2023. Potentially, the release could add new functionalities for universal generics, immutable data, and string templates, as well as finalise record pattern capabilities.

As of September 23, there are no officially proposed features listed on OpenJDK’s webpage for JDK 20, but this will change soon enough. Some of the capabilities that could be included in Java 20 are:

To unify the treatment of reference and primitive types in generic code, universal generics are being developed. There has been a proposal floating around for a while, and it didn’t make it into JDK 19.

The use of extent-local variables enables the sharing of immutable data between threads and within them.

Using string templates simplifies Java programming by making it easier to express strings that contain run-time values.

To enhance the Java object model with class instances that have only final instances and lack object identity, value objects are created.

Primitive classes define new primitive types, which are special kinds of value classes.

A sequenced collection is represented by a Collection interface, which defines the order of encounters in a collection.

Providing Java and native stack traces through an API for asynchronous stack traces.

Classfile API for parsing, generating, and transforming Java classes.

Record patterns are previewed in JDK 19, which can be used to deconstruct record values.

JDK 19 introduces a foreign function and memory API that enables Java programs to interact with code and data outside of the Java runtime.

JDK 19 preview also features virtual threads, which make it easier to write and maintain high-throughput concurrent applications.

As part of JDK 19, a vector API expresses vector computations which reliably compile at runtime to optimal instructions on supported CPU architectures, resulting in better performance than scalar computations.

Through an API, structured concurrency in JDK 19 simplifies multithreaded programming.

JDK 19 previews pattern matching for switch expressions and statements for a third time to enhance Java programming.

In March 2023, Java 20, or Java Development Kit 20, would arrive as a production release based on Java’s six-month release schedule. Similarly to JDK 19, Oracle will only provide premium support for six months for JDK 20. After a year, JDK 21 will be an LTS (Long Term Support) release backed by Oracle for several years.