Records and Sealed Types - Coming Soon to a JVM Near You!

OpenJDK's Project Amber has been delivering small improvements for a while now. With the release of Java 14, a group of major new features starts to arrive.

The first is Records - a new syntax for declaring a class that "just holds data" and fills the same role that tuples do in other programming languages. Coming soon are Sealed Types, which fundamentally change Java's model of object oriented programming by providing a middle way between classes that are final and classes that are completely open for extension. These seemingly unrelated ideas are not only powerful in their own right but are actually connected at a deep level. They light the way for further upcoming features, such as Pattern Matching (no, not regular expressions) and much, much more. Our journey will take in other recent changes in the Java language and will show how big ideas in language design sometimes start from surprisingly small implementation details.