Sealed classes (preview) in Java 15.

Overview

Sealed classes (preview) in Java 15.

Example 

  // Java 15 feature: Sealed classes (preview)
// See official JDK release notes for migration details

Common Use Cases

  • Modern Java 15 development
  • Migration from older JDK versions

Pitfalls to Avoid

  • Assuming feature availability on older JDKs
  • Not checking --release compiler flag
  • Java 14 features
  • JDK release notes

Best Practices

  • Understand when to use sealed classes (preview) versus simpler alternatives
  • Write unit tests covering edge cases and failure paths
  • Follow Java conventions and prefer standard library APIs when available
  • Profile before optimizing — measure impact in your specific workload