What's new in Java 21

Last Updated: 2023-03-02

Java 21 will likely be the next LTE version, to be released in 2023. This page summarizes changes in Java 18, 19, 20 and 21.

Spec / Language

Pattern Matching for switch

• JEP 420: Second Preview (JDK 18)
• JEP 427: Third Preview (JDK 19)
• JEP 433: Fourth Preview (JDK 20)

String Templates

• JEP 430: Preview (JDK 21)

Core Java Library

Project Panama: Vector API and Foreign Function & Memory API

The following updates are part of Project Panama, which improves connections between JVM and foreign / non-Java APIs.

• Vector API
  • JEP 417: Third Incubator (JDK 18)
  • JEP 426: Fourth Incubator (JDK 19)
  • JEP 438: Fifth Incubator (JDK 20)
• Foreign Function & Memory API
  • JEP 419: Second Incubator (JDK 18)
  • JEP 424: Preview (JDK 19)
  • JEP 434: Second Preview (JDK 20)

Project Loom

The following updates are part of Project Loom, which aims to bring fibers (lightweight threads) to Java.

• Virtual Threads
  • JEP 425: Preview (JDK 19)
  • JEP 436: Second Preview (JDK 20)
• Structured Concurrency
  • JEP 428: Incubator (JDK 19)
  • JEP 437: Second Incubator (JDK 20)
• Scoped Values
  • JEP 429: Incubator (JDK 20)

Project Amber

The following updates are part of Project Amber, which adds smaller, productivity-oriented Java language features.

• Record Patterns
  • JEP 405: Preview (JDK 19)
  • JEP 432: Second Preview (JDK 20)

Others

• JEP 400: UTF-8 by Default (java.nio.charsets) (JDK 18)
• JEP 408: Simple Web Server (java.net) (JDK 18)
• JEP 416: Reimplement Core Reflection with Method Handles (java.lang.reflect) (JDK 18)
• JEP 418: Internet-Address Resolution SPI (java.net) (JDK 18)
• JEP 421: Deprecate Finalization for Removal (java.lang) (JDK 18)

Tools

• JEP 413: Code Snippets in Java API Documentation (JDK 18)

Hotspot / Compiler

• JEP 422: Linux/RISC-V Port (JDK 19)