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.

The Design by Contract technique stresses the importance of explicitly specifying the constraints that hold before and after a software component executes.

Sealed classes make Java an even more powerful and expressive language and set the stage for even more sophisticated techniques such as pattern matching, which we'll explore in a subsequent article. A ...

The release of Java SE 15 in Sept 2020 will introduce "sealed classes" (JEP 360) as a preview feature. A sealed class is a class or interface which restricts which other classes or interfaces may ...

The Java object serialization example source code. The full code for this Java serialization tutorial is below. This is code uses a single public class and two non-public classes, all of which can be ...