Records with Sealed and Non-sealed Hierarchies in Java

 Records with Sealed and Non-sealed Hierarchies in Java

Java 17 introduced an enhancement to records that enables them to participate in sealed and non-sealed hierarchies. This feature allows records to be defined as sealed or non-sealed, and it also enables records to be used as permitted subclasses.

Example:

public sealed interface Animal permits Dog, Cat, Bird, Fish {

    record Dog() implements Animal {}

    record Cat() implements Animal {}

    non-sealed interface Bird extends Animal {}

    final class Fish implements Animal {}

}