This tutorial introduces the difference between classes and interfaces, then guides you through examples demonstrating how to declare, implement, and extend Java interfaces.

That hierarchy allows Sun Microsystems to easily distribute (and you to easily work with) those classes and interfaces. Examples of Java’s packages include: ...

Traditional Java 8 Predicate example While the Java 8 Predicate is a functional interface, there's nothing to stop a developer from using it in a traditional manner. Here's a Java Predicate example ...