Java 21 / JDK 21 (LTS) GA

Java 21 / JDK 21 has been officially GA. This version is the long-term support version (LTS) after JDK 17. Oracle will provide technical support and updates for at least eight years .

Formal stable features

• JEP 444: Virtual Threads
• JEP 431: Sequence Collections
• JEP 440: Recording Mode
• JEP 441: switch pattern matching
• JEP 439: Generational ZGC
• JEP 449: Deprecation of Windows 32-bit x86 port
• JEP 451: Prepare to disable dynamic loading of proxies
• JEP 452: Key Encapsulation Mechanism API

Preview phase functionality

• JEP 442: External Functions and Memory API (Third Preview)

• JEP 446: Scoped Values ​​(Preview)

• JEP 453: Structured Concurrency (Preview)

• JEP 430: String Templates (Preview)

• JEP 443: Unnamed patterns and variables (preview)

• JEP 445: Unnamed class and instance main methods (preview)

Incubation stage function

• JEP 448: Vector API (Incubator Phase 6)

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430:	String Templates (Preview)
431:	Sequenced Collections
439:	Generational ZGC
440:	Record Patterns
441:	Pattern Matching for switch
442:	Foreign Function & Memory API (Third Preview)
443:	Unnamed Patterns and Variables (Preview)
444:	Virtual Threads
445:	Unnamed Classes and Instance Main Methods (Preview)
446:	Scoped Values (Preview)
448:	Vector API (Sixth Incubator)
449:	Deprecate the Windows 32-bit x86 Port for Removal
451:	Prepare to Disallow the Dynamic Loading of Agents
452:	Key Encapsulation Mechanism API
453:	Structured Concurrency (Preview)

Download: https://jdk.java.net/21/
Release notes: https://jdk.java.net/21/release-notes
Features: https://openjdk.org/projects/jdk/21/