Java Tutorial: Modern Java
Records, sealed classes, pattern matching, text blocks, var, switch expressions, and what's new in Java 14-21.
Java, modernised
Java has evolved dramatically since Java 8. Records eliminate boilerplate. Sealed classes enforce hierarchies. Text blocks make multi-line strings readable. Virtual threads (Java 21) handle millions of concurrent connections.
These features make Java feel modern — reducing the verbosity that was its main criticism for decades.
What you'll learn in this Java modern java tutorial
This interactive Java tutorial has 6 hands-on exercises. Estimated time: 20 minutes.
- Records — immutable data classes — A `record` is an immutable data carrier. One line replaces: constructor, getters, equals, hashCode, toString:
- Text blocks — multi-line strings — Text blocks (Java 15+) make multi-line strings readable:
- Sealed classes — controlled hierarchies — A `sealed` class restricts which classes can extend it:
- Pattern matching switch — Java 21 brings full pattern matching in switch:
- Virtual threads (Java 21) — Virtual threads (Java 21) are lightweight — you can have MILLIONS:
- Build a modern API response model — Final challenge — no starter code.
Java Modern Java concepts covered
- Java, modernised