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

Most introductory Java texts take an implementation-centric stab at how to use interfaces and abstract classes. However, few provide a clear design distinction for choosing between these two ...

How does the open-closed SOLID principle work in a Java program? Here we show you what this important principle means, and how to implement the open-closed principle in Java.