JDK 21 has entered the first phase of Rampdown and officially forked from the main line. This is another LTS version after JDK 17.
After entering the first stage of Rampdown, the entire feature set is frozen. With the exception of one working JEP that will be discarded, this release will contain no changes to JEPs and instead focus on bug fixes and other approved enhancements.
The JDK 21 version has a total of 15 JEPs, which is more than twice that of JDK 20. This release brings stable virtual threads functionality, string templates in preview, the third preview of the Java external functions and memory API, the latest iteration of the Java Vector API, structured concurrency in preview, and more.
New features include Key Encapsulation Mechanism API Key Encapsulation Mechanism API , Generational ZGC of Z Garbage Collector , Sequenced Collections of serialized collections, and JEP 445 , which strives to simplify the writing of Hello World ... (Details about JEP 445 can be found at Check out this article: JAVA New Proposal: Efforts to Simplify Hello World Writing )
The initial release candidate of JDK 21 will be released in August, the second release candidate will be released in late August, and the current GA target for JDK 21 is September 19. We will introduce each function in detail when JDK 21 is officially GA.