Learn the difference between classes and interfaces once and for all, then get started declaring, implementing, and extending interfaces in your Java programs ...

Java lets you declare interfaces inside of classes. Once declared, an interface is automatically a static member of the class. There is no need to declare the interface with the static keyword.

Learn what a predicate interface is and how to use it in Java. Find out how to create your own custom predicate interface and combine it with other predicates.

A customizer class provides a complete custom GUI for customizing a target Java Bean. Each customizer should inherit from the java.awt.Component class so it can be instantiated inside an AWT dialog or ...