Groovy Recipes: Greasing the Wheels of Java by Scott Davis
Each recipe in Groovy Recipes begins with a concise code example for a quick start, followed by in-depth explanation in plain English. These recipes will get you to-to-speed in a Groovy environment quickly. You'll see how to speed up nearly every aspect of the development process using Groovy. Groovy makes mundane file management tasks like copying and renaming files trivial. Reading and writing XML has never been easier with XmlParsers and XmlBuilders. Breathe new life into Arrays, Maps, and Lists with a number of convenience methods. But Groovy does more than just ease traditional Java development: it brings modern programming features to the Java platform like closures, duck-typing, and metaprogramming.