4.1 Overview
Modern Java models domains with two key constructs: records for value-centric data and sealed types for constrained hierarchies. This chapter provides a practical path to design expressive, safe APIs and domain models.
You will learn:
- When to choose classes vs records
- How to enforce invariants via compact constructors
- How sealed hierarchies enable exhaustive
switchhandling - How record patterns power concise, declarative logic
- Real-world examples that tie patterns to production code
Navigate using the sections that follow for deeper dives.