Getting started 5 lessons

1 Getting Started with Groovy What Groovy is, how to install it, and three ways to run Groovy code — the console, the shell and scripts. Beginner2 min read 2 Groovy Syntax Essentials The shortcuts that make Groovy concise — def, optional semicolons and parentheses, implicit returns, default parameters, exact decimals and == that compares values. Beginner3 min read 3 Strings and GStrings Build text with interpolation, write multi-line strings and regular expressions without escaping, and use Groovy's extra String methods. Beginner2 min read 4 Lists, Maps and Ranges Create and manipulate lists and maps with literal syntax, slice them with ranges and negative indexes, and navigate nested JSON-like data with the spread operator. Beginner3 min read 5 Control Flow and Groovy Truth Learn which values count as true or false in Groovy, use the Elvis operator for defaults, and write switch statements that match types, regexes, lists and closures. Beginner3 min read

Closures 3 lessons

6 Closures: The Basics Learn Groovy's most important feature — closures — how to write them, call them, pass them to methods, and how they capture variables. Intermediate3 min read 7 Advanced Closures: delegate, Currying, Composition and memoize Go beyond the basics — understand this, owner and delegate (the secret behind Groovy DSLs), and use currying, composition, memoization and trampolines. Advanced4 min read 8 Functional Collection Methods: each, collect, findAll, inject and groupBy Process collections the Groovy way — transform, filter, search, total, group and batch data with closures instead of loops. Intermediate4 min read

Real-world Groovy 5 lessons

9 Null Safety: ?., ?: and Friends Navigate data that might be missing without NullPointerExceptions, using safe navigation, Elvis defaults and Elvis assignment. Intermediate2 min read 10 Classes, Properties and Traits Write Groovy classes without boilerplate — automatic properties, named-argument constructors, AST transformations like @Canonical, and reusable behaviour with traits. Intermediate3 min read 11 Working with JSON and XML Parse and build JSON and XML in a few lines with JsonSlurper, JsonOutput, XmlSlurper and MarkupBuilder — the everyday tools of integration scripting. Intermediate3 min read 12 Files and I/O Read and write files in one line, process big files line by line, parse CSV with headers, and clean up safely. Beginner3 min read 13 Groovy in Boomi: Scripts for Integrations Put everything together in the context where many integration developers meet Groovy first — Boomi Data Process scripts — with a version you can run on your own machine. Advanced4 min read