Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

Create packages, import packaged classes and interfaces into your programs, move packages, and encapsulate them in jar files.

There is a reason why Java method modifiers exist. If you call public methods internally and don't understand why, your developers could face major class issues.

The implementation of Java 8 Lambda expressions required an introduction to a number of new interfaces with esoteric names that can be somewhat intimidating to developers without any experience in ...