Java interfaces are different from classes, and it’s important to know how to use their special properties in your Java programs. This tutorial introduces the difference between classes and interfaces ...

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

If you want to take advantage of sorting methods in Java, you'll need to implement the Comparable interface.

One day, there will be a full increment release of Java, and when that two-point-oh version becomes official, I am desperately hoping they will include a fully implemented toString() method in the ...