Groovy is a powerful multi-faceted programming language for the JVM platform. It supports a spectrum of programming styles incorporating features from dynamic languages such as optional and duck typing, but also static compilation and static type checking at levels similar to or greater than Java through its extensible static type checker. It aims to greatly increase developer productivity with many powerful features but also a concise, familiar and easy to learn syntax.
It integrates smoothly with any Java class or library, and immediately delivers to your application powerful capabilities, including scripting support, Domain-Specific Language authoring, runtime and compile-time meta-programming and functional programming.
Obtaining the Source
You don’t need the source code to use Apache Groovy but if you wish to explore its inner workings or build it for yourself there are two ways to obtain the source files.
Checking out from Version Control
Apache Groovy uses Git. The official Git repository is at:
And a mirror is hosted on Github:
The Github mirror is read-only and provides convenience to users and developers to explore the code and for the community to accept contributions via Github pull requests.
git clone the repo (or the repo you forked via the github website) and you will have the complete source.
Unpacking the src distribution
Alternatively, you can download the source distribution and unpack it.
As mentioned in the previous paragraph, if you download the source distribution you need to bootstrap Gradle. This isn’t needed if you clone from the Github repo.
Each version of Groovy is built and tested using a specific version of Gradle.
That version is specified by the
gradle_version property defined in the
file within the root directory. Luckily you shouldn’t need to know that version and,
after bootstrapping, you should use the
gradlew command which will ensure the
correct version is always used.
The version of Gradle used for the bootstrap step has some flexibility though in general you might need to download a version similar to the version of Groovy the build is expecting.
To bootstrap Gradle, at the top directory of your unpacked source, run the command:
gradle -b wrapper.gradle wrapper
On Unix-like systems, use
If the version of Gradle you have installed is close to the required version,
you might be able to get away without the
-b wrapper.gradle above, but if in
doubt leave it in.
NOTE: At this point, the Gradle wrapper should be set up and from now on you should use
gradlew command instead of
gradle. (On Unix-like systems, use
Building from Source
To build you will need:
To build everything using Gradle, use the following command (
./gradlew on Unix-like systems):
gradlew clean dist
Note: The gradlew command automatically downloads the correct Gradle version if needed, you do not need to download it first.
This will generate a distribution similar to the zip you can download on the Groovy download page.
To build everything and launch unit tests, use:
If you want to launch one unit test, use this. <TestClassName> is like
gradlew :test --tests <TestClassName>
To build from IntelliJ IDEA:
gradlew jar idea
Then open the generated project in IDEA.
To build from Eclipse:
gradlew jar eclipse
Then open the generated project and the generated subprojects in Eclipse. But be aware that Eclipse tends to be more limited in its ability to reproduce a Gradle build structure. The generated project files may contain a circular dependency which may or may not prevent Eclipse from using them. It depends on the Eclipse version, if this is an issue or not.
To build the documentation (Groovy Language Documentation):
All code samples of the documentation guide are pulled from actual test cases. To run a single documentation test case, take for example
(Note the omission of package name: class is
semantics.PowerAssertTest but only
PowerAssertTest is added to
The Groovy build supports the JVM instruction
invokedynamic. If you want to build Groovy with invokedynamic, you can use the project property
gradlew -Pindy=true clean test
Please note that the following Gradle tasks generate both indy and non indy variants of the jars, so you don’t need to use the system property:
Groovy core team tunes performance through YourKit Java Profiler, which is sponsored by YourKit.
Friends of Groovy Open Collective
As an independent initiative, we have set up an open collective for Groovy:
This initiative is designed to complement the Apache project and the many contributions we get from our great community and supporters.
Thank you to our Silver Sponsors:
Thank you to our Bronze Sponsors:
Thank you to our backers(donating monthly):
Thank you to all our backers:
Groovy is licensed under the terms of the Apache License, Version 2.0