Java Optional.flatMap() is a method in the Java Optional class that allows for transforming the value inside the Optional if it is present, applying a function that returns another Optional. It helps to chain multiple operations on optional values. Introduced in Java 2014 with Java 8, flatMap() is part of Java's functional programming features, facilitating cleaner handling of null or missing values.

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