What’s New in JDK 20? A Quick Look at the Latest Java Features

JDK 20 (Java 20) has been officially released. Although the version number is impressive, the new features are mostly refinements of previously previewed capabilities.

JDK 20 is a short‑term support release with six months of maintenance and can be used in production environments.

The next LTS version, JDK 21, is scheduled for release in September 2023.

This release includes seven JEPs at various incubation and preview stages, along with hundreds of minor enhancements and thousands of bug fixes:

JEP 429: Scoped Values (Incubator)

JEP 432: Record Patterns (Second Preview)

JEP 433: Pattern Matching for switch (Fourth Preview)

JEP 434: Foreign Function & Memory API (Second Preview)

JEP 436: Virtual Threads (Second Preview)

JEP 437: Structured Concurrency (Second Incubator)

JEP 438: Vector API (Fifth Incubator)

Scoped Values (Incubator)

Scoped Values allow sharing immutable data within and across threads, offering advantages over thread‑local variables, especially when using many virtual threads.

Record Patterns (Second Preview)

Record Patterns enable deconstruction of record values; combined with type patterns, they allow powerful, declarative, composable data navigation and handling.

Pattern Matching for switch (Fourth Preview)

Pattern matching extends switch expressions and statements, allowing patterns to be tested in switch, making complex data‑centric queries concise and safe.

Foreign Function & Memory API (Second Preview)

This API lets Java programs interoperate with code and data outside the Java runtime, calling native libraries and accessing native memory safely, avoiding the pitfalls of JNI.

Virtual Threads (Second Preview)

Virtual threads are lightweight threads implemented by the JDK, similar to Go’s goroutines or Erlang processes, reducing context‑switch overhead and simplifying high‑concurrency programming.

Structured Concurrency (Second Incubator)

Structured concurrency treats multiple tasks running in different threads as a single unit of work, simplifying error handling, improving reliability, and enhancing observability while preserving the readability of single‑threaded code.

Vector API (Fifth Incubator)

The Vector API expresses vector computations that the runtime can compile to optimal vector instructions on supported CPUs, delivering performance superior to equivalent scalar code while providing a platform‑independent, easy‑to‑use API.

More details can be found at https://openjdk.org/projects/jdk/20/.

Download the JDK at https://jdk.java.net/20/.