There are over 40 functional interfaces listed in the java.util.functions package, which can make the prospect of functional programming in Java a somewhat daunting task.

Functional supplier interface in Java tutorial There are only half a dozen classes you really need to master to become competent in the world of functional programming. The java.util.function package ...

Rewrite object-oriented code using functional techniques. Get started with lambdas, method references, functional interfaces, and the Streams API in Java ...

Get a deep dive into using method references in your Java programs, including stream operations, event listeners, and constructors and factories.