Java SE 14 (March 2020) introduced a limited form of pattern matching as a preview feature, which becomes a permanent feature in Java SE 16 (March 2021).

JEP 443, Unnamed Patterns and Variables (Preview), has been Completed from Targeted status for JDK 21. This preview JEP proposes to "enhance the language with unnamed patterns, which match a ...

Java 23 extends import and patterns, but dispenses with string templates In addition to enhanced preview features such as the Class-File API, the JDK brings innovations in pattern matching and ...

The Observable design pattern is found in many Java APIs and in reactive programming. Here's an introduction to the timeless Observable pattern in Java.