Groovy immutable objects with @Immutable annotation to create immutable objects with 10+ examples. Defensive copies, known types, copyWith, and thread-safe value objects. “Immutable objects are always thread-safe. If you can make your objects immutable, you eliminate an entire category of concurrency bugs.” Effective Java, Joshua Bloch Last Updated: March 2026 | Tested on: Groovy 5.x, Java 17+ | Difficulty: Intermediate | Reading Time: 18 minutes Creating truly immutable objects in Java requires a checklist: final class, final private fields, no ... Read More