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  • is an agile and dynamic language for the Java Virtual Machine
  • builds upon the strengths of Java but has additional power features inspired by languages like Python, Ruby and Smalltalk
  • makes modern programming features available to Java developers with almost-zero learning curve
  • provides the ability to statically type check and statically compile your code for robustness and performance
  • supports Domain-Specific Languages and other compact syntax so your code becomes easy to read and maintain
  • makes writing shell and build scripts easy with its powerful processing primitives, OO abilities and an Ant DSL
  • increases developer productivity by reducing scaffolding code when developing web, GUI, database or console applications
  • simplifies testing by supporting unit testing and mocking out-of-the-box
  • seamlessly integrates with all existing Java classes and libraries
  • compiles straight to Java bytecode so you can use it anywhere you can use Java

Experience Groovy 2.3

Groovy 2.3 is the latest major and stable version of the popular alternative language for the JVM.

In this new release, Groovy features:

  • official support for running Groovy on JDK 8
  • traits, as a new object oriented way of composing behavior in your classes
  • new and improved AST transformations like @TailRecursive, @Builder and @Sortable
  • a new NIO2 module with Path support
  • lightening fast JSON parsing and building
  • closure parameter type inference
  • a new markup template engine
  • Groovysh and GroovyConsole ease of use improvements
  • a new GroovyAssert test utility
  • more @BaseScript class capabilities, and more.

Deprecating the wiki


We are slowly migrating documentation from the wiki to a new website. It is recommanded that you read the new documentation first, and fall back to the wiki if you can't find what you were looking for.



"Groovy is like a super version of Java. It can leverage Java's enterprise capabilities but also has cool productivity features like closures, builders and dynamic typing. If you are a developer, tester or script guru, you have to love Groovy."



A simple hello world script:

def name='World'; println "Hello $name!"

A more sophisticated version using Object Orientation:

class Greet {
  def name
  Greet(who) { name = who[0].toUpperCase() +
                      who[1..-1] }
  def salute() { println "Hello $name!" }

g = new Greet('world')  // create object
g.salute()               // output "Hello World!"

Leveraging existing Java libraries:

import static org.apache.commons.lang.WordUtils.*

class Greeter extends Greet {
  Greeter(who) { name = capitalize(who) }

new Greeter('world').salute()

On the command line:

groovy -e "println 'Hello ' + args[0]" World


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Latest news [more]

Groovy 2.3.0 is out

The Groovy development team is proud to announce the final release of Groovy 2.3.0!

 Groovy 2.3 is the new major release of Groovy, featuring official support for running Groovy on JDK 8traits, new and improved AST transformations like @TailRecursive@Builder and @Sortable, a new NIO2 module with Path support, lightening fast JSON parsing and building, closure parameter type inference, a new markup template engine, Groovysh and GroovyConsole ease of use improvements, a new GroovyAssert test utility, more @BaseScript class capabilities, and more.

Please read the Groovy 2.3.0 release notes for further details on all these exciting new features!

You can download Groovy at the usual location.

JIRA will give you the detailed change log for this release.

Groovy wouldn’t be what it is without your support, your bug reports and feature requests, your contributions and pull requests, so big thanks to all those who contributed to this release in a way or another, including the usual suspects of the core team (Jochen, Paul, Cédric and myself), but also André, Andres, Tim, Pascal, Johanes, Paolo, Thibault, Rick and Andrey, Jim (base script class), Damien, Kenneth and several others I’ve forgotten to mention!


  1. Hi,

    I am unable to get the example that you have posted on InfoQ for using the tripple dot notation of variable args list. i.e I cut and pasted the following code

    into groovyconsole and I get the following:

    Exception thrown: org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed, Script14: 1: unexpected token: ... @ line 1, column 21.
    1 error
    org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed, Script14: 1: unexpected token: ... @ line 1, column 21.
    1 error

    Am I missing something?



  2. Vimal,

    I tried it, but now i get another error:

    groovy.lang.MissingMethodException: No signature of method: java.lang.Integer.size() is applicable for argument types: () values: {}
    	at Script14.sum(Script14:3)
  3. Vimal, try this:

  4. Oh,in Groovy1.6.0b2,  following line CAN'T run:

    $groovy -e "println 'Hello ' + args[0]" World

    Caught: groovy.lang.MissingPropertyException: No such property: args for class: script_from_command_line

    It's just on groovy's HOMEPAGE !

  5. James, this is a known problem, and a JIRA issue was raised.

    This regression will be fixed for Groovy 1.6-rc-1.

    Sorry for the inconvenience.

  6. Thanks glaforge.  I've fixed my Groovy 1.6b2 with your method. Open source is great!

  7. What about shortening the names for things in Groovy? like Maven has the mvn command.


    groovy => gv

    groovyc => gvc

    groovysh => gvsh

    groovlet script => gvp (isn't it sort of  jsp like stuff?)


    (then rewrite the old ones to call the new-names for backward compatibility)

  8. (9/24/2009 - fixed blog so that the linked entry displays properly in web browser)

    There are times when we need to read a single record at a time from a file.
    Eg., if we want to stop reading a file at a certain point.
    Or when working with more than one file. After comparing records, one might have to read a record from one or the other file, or from both.

    I was not able to find good documentation on how to do this.
    By spending a lot of time searching and experimenting, I was able to find out how to do it.


     Note that it requires two executions of .readLine for each record, but that is easy to get around, but putting it in a closure, as shown. This would usually be done anyway, to include things like record counts and end-of-file logic. So in a real program, each readALine closure would have two readLine statements.

  9. When I put the following in my initialization routine, highValue was undefined elsewhere
         String highValue = '\377'

    So I changed the code to the following two lines, which worked
         String highValue2 = '\377'
         highValue = highValue2

    When I replaced these two lines by the following, it was again undefined elsewhere
         public String highValue = '\377'

    Is there a way to define a global typed variable with a single statement?