The Java Tutorial goes on to list bullets for when an abstract class should be considered and for when an interface should be considered. Unsurprisingly, these are derived from the previously ...

For example, the Matcher class, in java.util.regex, provides a results() ... Nested interfaces and classes. Java also lets you nest interfaces in interfaces and classes in interfaces.

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 ...

Implementation of the UnaryOperator example. To show you an old school, pre-Java 8 UnaryOperator example, we will create a single class named UnaryOperatorExample and provide the required apply method ...