Inheritance

There are two ways to handle object inheritance in Java: interfaces and abstract classes.

Abstract Classes

The easiest way is using abstract classes, but each class can inherit from a single abstract. On the other hand an abstract class can contain code.

Any class can inherit from many interfaces, but these contain no code. Instead they offer a common set of methods for the class.

It is recommended using an interface before an abstract class, as this will decouple code from more specific implementations.

Avoid adding constants to interfaces.

By using interfaces the code can be made easier to test, as implementations can be swapped with few problems.

In a similar way to testing, interfaces make it easier injecting dependencies, and swapping them.

object instanceof ClassName

ClassName.class.isAssignableFrom(object)

Last updated 4 years ago