Sealed Classes & Interfaces (Java 17)

Understanding how to manage class hierarchies effectively is crucial in any object-oriented programming language. With Java 17 introducing sealed classes and interfaces, we gain a powerful tool for controlling which classes can extend or implement our base types.

This feature is particularly useful for creating more predictable and maintainable code, especially in systems that involve complex type hierarchies.

In this chapter, we'll dive deep into sealed classes and interfaces in Java 17. We'll explore how they work, why you might want to use them, and provide practical examples to illustrate their benefits.