It is worth noting that JEP 438 was added to the feature set in early March 2023. As per the release schedule, JDK 20 will be formally released on March 21, 2023.

Critical bugs, such as regressions or serious functionality issues, may be addressed, but must be approved via the Fix-Request process. The main-line source repository, forked to the JDK stabilization repository in mid-December 2022 (Rampdown Phase One), defines the feature set for JDK 20. The proof of concept patch for the library-based solution is also available.JDK 20, the third non-LTS release since JDK 17, has reached its initial release candidate phase as declared by Mark Reinhold, chief architect, Java Platform Group at Oracle. The value types make library-based solutions for Map far more practical too. The Static methods in an interface make the library-based solution more practical. But this approach still lacks a reasonable way to describe pair literals as Maps. The library-based solutions are more acceptable for Lists, Sets and Arrays. This includes more efficient varargs, array constants in the constant pool, immutable arrays, and support for caching (and reclaiming under pressure) intermediate immutable results.Īccording to Oracle’s Brian Goetz, the real pain is in Maps not Lists, Sets or Arrays. It is better off focusing Oracle’s language-design bandwidth on addressing foundational issues underlying a library-based version.It is better not to try collection literal before the value types. The value types are coming and the behavior of this new feature (collection literals) with the value types is not known.The library-based approach gives X% of the benefit for 1% of the cost, where X > 1.The library-based changes would remove much of the requirement for the “collection literals” change discussed in Project Coin.

The advanced solution to cover an extensible set of other collection types is open-ended, messy, and virtually guaranteed to way overrun its design budget. The basic solution of this feature works only for Sets, Lists and Maps so it is not very satisfying or popular.The Implementation would ideally be via new dedicated immutable classes.įollowing are the major points behind this library-based approach. As an alternative Oracle suggests a library-based proposal based on the concept of static methods on interfaces.

Java jdk 1.8