Java Optional.stream() is a method in the Java Optional class that returns a Java Stream containing the value inside the Optional if present, or an empty stream if not. It is useful for chaining Java Stream operations with optional values, supporting a more functional style of programming. Introduced in Java 2014 with Java 8, stream() is widely used to handle Optional values in Java's functional programming ecosystem.

https://docs.oracle.com/javase/8/docs/api/java/util/Optional.html