Groovy Metaprogramming

Groovy metaprogramming tutorials. Runtime and compile-time techniques including MetaClass, ExpandoMetaClass, categories, mixins, and AST transforms.

Groovy AST Transformations – Compile-Time Code Generation with 10+ Examples

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Groovy AST transformations for compile-time code generation. 10+ examples covering @ToString, @EqualsAndHashCode, @Canonical, @Delegate, and custom ASTs. “The best code is code you never write. AST transformations generate boilerplate at compile time so you can focus on what matters.” Groovy Metaprogramming Philosophy Last Updated: March 2026 | Tested on: Groovy 5.x, Java 17+ | Difficulty: Intermediate to Advanced | Reading Time: 20 minutes Every developer knows the pain of writing toString(), equals(), hashCode(), constructors, and getters/setters for every class. It’s ... Read More

Groovy Traits Tutorial – Reusable Behavior Composition with 10+ Examples

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Learn Groovy traits for reusable behavior composition with 10+ tested examples. Trait methods, fields, interfaces, conflicts, and runtime traits on Groovy 5.x. “Favor composition over inheritance. Traits give you the best of both worlds – you compose behavior like interfaces but with real implementation.” Guillaume Laforge, Groovy Project Lead Last Updated: March 2026 | Tested on: Groovy 5.x, Java 17+ | Difficulty: Intermediate | Reading Time: 18 minutes Sharing behavior across classes that don’t share a common ancestor is painful ... Read More

Groovy @Immutable Annotation – Create Immutable Objects with 10+ Examples

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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