Groovy is a dynamic programming language for the JVM that combines Java’s enterprise capabilities with productivity features like closures, builders, dynamic typing and meta-programming. It can either be interpreted or compiled and you can add new methods to classes dynamically at run time, with greater flexibility than standard Java offers. There seems to be an increasing interest in Groovy so I looked around for some quality Groovy tutorials, and here are a few that make the grade. You might want to bookmark this article, as I will actively maintain this list of tutorials, as I do with Digital Media Minute’s well-received ruby on rails tutorial listings.
The best place to start is codehaus.org, which has links to all things Groovy, including a very comprehensive set of Groovy tutorials. You’ll also find a download for the latest stable version, user guides developer and testing guides, cookbook examples of Groovy, and an advanced usage guide.
This Groovy tutorial by Lars Bogle is quite comprehensive, covering installation, your first project and some example usage. Groovy classes objects and methods, loops and datatypes are covered in the introductory chapters, then Vogel moves on to a section on Grails, Groovy classes in Java and using the language via the command line. This is one of the longer and more professional Groovy tutorials on the Internet at the moment.
Over at skill-guru.com you will find a series of task-specific Groovy and Grails tutorials, for instance on topics like Groovy closures, calling a stored procedure, and creating and running your first application in Grails.
Guillaume Laforge at the Springsource blog has an excellent long tutorial on building your first Groovy-powered Google app engine web application.
At IBM developerWorks, Scott Davis has written several Grails and Groovy tutorials in the form of modules on topics like meta-programming with closures, ExpandoMetaClass and categories, and building a Grails application.
NetBeans has a brief tutorial on getting started with Groovy in NetBeans IDE.
Chris Judd and Jim Shingler have a very lengthy slideshare presentation on Groovy and Grails taken from CodeMash 2009.
Here’s another Groovy tutorial from IBM’s developerWorks on exactly how you can incorporate the language into your Java programming.