Modern OOP: Sealed Hierarchies, Records & Pattern Matching
Master modern Java 21 OOP paradigms. Replace boilerplate with Records, restrict inheritance with Sealed Classes, and leverage Pattern Matching.
Understanding of classes, objects, and reference semantics
Expertise in Java 21 object modeling: immutable Records, Sealed hierarchies, and pattern-matching switches.
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Every lesson builds on the one before it. Open any lesson to read the explanation, run the examples, and try the practice challenges.
- 03.01Core OOP Principles & Dynamic Method Dispatch4 min
Revisit object-oriented foundations. Understand encapsulation, inheritance trade-offs, virtual method tables (vtable), and dynamic polymorphism.
- 03.02Java 21 Records: Transparent Data Carriers & Canonical Serialization4 min
Eliminate boilerplate with Java Records. Master compact constructors, canonical constructors, immutability guarantees, and record reflection.
- 03.03Sealed Hierarchies & Exhaustive Pattern Matching in Java 214 min
Master modern algebraic data modeling. Restrict inheritance with sealed classes, eliminate visitor patterns, and leverage exhaustive pattern matching for switch.
- 03.04Modern GoF Patterns: Builder, Factory, and Visitor via Pattern Matching4 min
Re-architect classic Gang of Four design patterns using modern Java 21 idioms: immutable Records, Sealed class hierarchies, and exhaustive pattern-matching switches.
Ready to move on?
Refactor a legacy inheritance hierarchy into sealed interfaces with exhaustive pattern matching.
Open the module self-check