A class implements an interface by appending Java’s implements keyword followed by a comma-separated list of interface names to the class header, and by coding each interface method in the class.

In other words, a Java class that supports the SOLID open-closed principle will find use in originally un-envisioned scenarios, and be flexible enough to work with newly created classes, interfaces ...

Inside of a main method or any other piece of Java code, the SimpleConsumerExample class can be instatiated according to traditional Java syntax rules: /* Java Consumer example using a class */ ...