Programming Groovy 2: Dynamic Productivity for the Java Developer - Subramaniam Venkat

"Groovy brings you the best of both worlds: a flexible, highly productive, agile, dynamic language that runs on the rich framework of the Java Platform. Groovy preserves the Java semantics and extends the JDK to give you true dynamic language capabilities. Programming Groovy 2 will help you, the experienced Java developer, learn and take advantage of the latest version of this rich dynamic language. You'll go from the basics of Groovy to the latest advances in the language, including options for type checking, tail-call and memoization optimizations, compile time metaprogramming, and fluent interfaces to create DSLs.
You don't have to leave the rich Java Platform to take advantage of Groovy. Groovy preserves Java's semantics and extends the JDK, so programming in Groovy feels like the Java language has been augmented; it's like working with a lighter, more elegant