Groovy

Groovy

Groovy v4 adds Switch Expressions, Records, and Sealed Types. It remains the key to Gradle and Jenkins Pipelines.

When to Use

• Build Automation: Writing build.gradle scripts.
• CI/​CD: Writing Jenkinsfiles.
• Scripting JVM: Interacting with Java libraries dynamically.

Core Concepts

Closures

{ item -> item.name }. The core functional primitive.

Dynamic Typing

def x = 1. (Though @CompileStatic can force types).

Builders

JsonBuilder, MarkupBuilder for generating hierarchical data.

Best Practices (2025)

Do:

• Use @CompileStatic: For performance critical code (production logic).
• Use Spock: The best testing framework on the JVM (written in Groovy).
• Use def sparingly: Type your variables if you know them.

Don't:

• Don't mix logic in Gradle: Keep build scripts declarative. Move logic to buildSrc.

References

• Apache Groovy