Gradle Build Language Reference

Version 1.0

Introduction

This reference guide describes the various types which make up the Gradle build language, or DSL.

Some basics

There are a few basic concepts that you should understand, which will help you write Gradle scripts.

First, Gradle scripts are configuration scripts. As the script executes, it configures an object of a particular type. For example, as a build script executes, it configures an object of type Project. This object is called the delegate object of the script. The following table shows the delegate for each type of Gradle script.

Type of script Delegates to instance of
Build script Project
Init script Gradle
Settings script Settings

The properties and methods of the delegate object are available for you to use in the script.

Second, each Gradle script implements the Script interface. This interface defines a number of properties and methods which you can use in the script.

Build script structure

A build script is made up of zero or more statements and script blocks. Statements can include method calls, property assignments, and local variable definitions. A script block is a method call which takes a closure as a parameter. The closure is treated as a configuration closure which configures some delegate object as it executes. The top level script blocks are listed below.

BlockDescription
allprojects { }

Configures this project and each of its sub-projects.

artifacts { }

Configures the published artifacts for this project.

buildscript { }

Configures the build script classpath for this project.

configurations { }

Configures the dependency configurations for this project.

dependencies { }

Configures the dependencies for this project.

repositories { }

Configures the repositories for this project.

sourceSets { }

Configures the source sets of this project.

subprojects { }

Configures the sub-projects of this project.

A build script is also a Groovy script, and so can contain those elements allowed in a Groovy script, such as method definitions and class definitions.

Core types

Listed below are some of the central types which are used in Gradle scripts:

TypeDescription
Project

This interface is the main API you use to interact with Gradle from your build file. From a Project, you have programmatic access to all of Gradle's features.

Task

A Task represents a single atomic piece of work for a build, such as compiling classes or generating javadoc.

Gradle

Represents an invocation of Gradle.

Settings

Declares the configuration required to instantiate and configure the hierarchy of Project instances which are to participate in a build.

Script

This interface is implemented by all Gradle scripts to add in some Gradle-specific methods. As your compiled script class will implement this interface, you can use the methods and properties declared by this interface directly in your script.

SourceSet

A SourceSet represents a logical group of Java source and resources.

SourceSetOutput

A collection of all output directories (compiled classes, processed resources, etc.) - notice that SourceSetOutput extends FileCollection.

Configuration

A Configuration represents a group of artifacts and their dependencies. Find more information about declaring dependencies to a configuration or about managing configurations in docs for ConfigurationContainer

ResolutionStrategy

Defines the strategies around dependency resolution. For example, forcing certain dependency versions, conflict resolutions or snapshot timeouts.

ConventionProperty

ConventionProperty can be assigned but cannot be mutated (even if the object is mutable!)

ExtensionAware

Objects that can be extended at runtime with other objects.

ExtraPropertiesExtension

Additional, ad-hoc, properties for Gradle domain objects.

Container types

Container types that handle various declarative elements (e.g. dependencies, configurations, artifacts, etc.):

TypeDescription
ConfigurationContainer

A ConfigurationContainer is responsible for declaring and managing configurations. See also Configuration.

DependencyHandler

A DependencyHandler is used to declare dependencies. Dependencies are grouped into configurations (see Configuration).

ArtifactHandler

This class is for defining artifacts to be published and adding them to configurations. Creating publish artifacts does not mean to create an archive. What is created is a domain object which represents a file to be published and information on how it should be published (e.g. the name).

Task types

Listed below are the various task types which are available for use in your build script:

TypeDescription
AntlrTask

Generates parsers from Antlr grammars.

Checkstyle

Runs Checkstyle against some source files.

CodeNarc

Runs CodeNarc against some source files.

Compile

Compiles Java source files.

Copy

Copies files into a destination directory. This task can also rename and filter files as it copies. The task implements CopySpec for specifying what to copy.

CreateStartScripts

A Task for creating OS dependent start scripts.

Delete

Deletes files or directories. Example:

Directory

Creates a directory.

DependencyReportTask

Displays the dependency tree for a project. Can be configured to output to a file, and to optionally output a graphviz compatible "dot" graph. An instance of this type is used when you execute the dependencies task from the command-line.

Ear

Assembles an EAR archive.

Exec

Executes a command line process. Example:

FindBugs

Analyzes code with FindBugs.

GradleBuild

Executes a Gradle build.

GroovyCompile

Compiles Groovy source files, and optionally, Java source files.

Groovydoc

Generates HTML API documentation for Groovy source, and optionally, Java source.

Jar

Assembles a JAR archive.

Javadoc

Generates HTML API documentation for Java classes.

JavaExec

Executes a Java application in a child process.

JDepend

Analyzes code with JDepend.

JettyRun

Deploys an exploded web application to an embedded Jetty web container. Does not require that the web application be assembled into a war, saving time during the development cycle.

JettyRunWar

Deploys a WAR to an embedded Jetty web container.

JettyStop

Stops the embedded Jetty web container, if it is running.

Pmd

Runs a set of static code analysis rules on Java source code files and generates a report of problems found.

PropertyReportTask

Displays the properties of a project. An instance of this type is used when you execute the properties task from the command-line.

ProjectReportTask

Displays a list of projects in the build. An instance of this type is used when you execute the projects task from the command-line.

ScalaCompile

Compiles Scala source files, and optionally, Java source files.

ScalaDoc

Generates HTML API documentation for Scala source files.

Sign

A task for creating digital signature files for one or more; tasks, files, publishable artifacts or configurations.

SonarAnalyze

Analyzes a project hierachy and writes the results to the Sonar database.

Sync

Synchronises the contents of a destination directory with some source directories and files.

Tar

Assembles a TAR archive.

TaskReportTask

Displays a list of tasks in the project. An instance of this type is used when you execute the tasks task from the command-line.

Test

Executes tests. Supports JUnit (3.8.x or 4.x) or TestNG tests.

Upload

Uploads the artifacts of a Configuration to a set of repositories.

War

Assembles a WAR archive.

Wrapper

Generates scripts (for *nix and windows) which allow you to build your project with Gradle, without having to install Gradle.

Zip

Assembles a ZIP archive.

Eclipse/IDEA model types

Used to configure Eclipse or IDEA plugins

TypeDescription
EclipseModel

DSL-friendly model of the Eclipse project information. First point of entry when it comes to customizing the eclipse generation

EclipseProject

Enables fine-tuning project details (.project file) of the Eclipse plugin

EclipseClasspath

Enables fine-tuning classpath details (.classpath file) of the Eclipse plugin

EclipseJdt

Enables fine-tuning jdt details of the Eclipse plugin

EclipseWtp

Enables fine-tuning wtp/wst details of the Eclipse plugin

EclipseWtpComponent

Enables fine-tuning wtp component details of the Eclipse plugin

EclipseWtpFacet

Enables fine-tuning wtp facet details of the Eclipse plugin

IdeaModel

DSL-friendly model of the IDEA project information. First point of entry when it comes to customizing the IDEA generation.

IdeaProject

Enables fine-tuning project details (*.ipr file) of the IDEA plugin.

IdeaModule

Enables fine-tuning module details (*.iml file) of the IDEA plugin .

IdeaWorkspace

Enables fine-tuning workspace details (*.iws file) of the IDEA plugin.

XmlFileContentMerger

Models the generation/parsing/merging capabilities. Adds xml-related hooks.

FileContentMerger

Models the generation/parsing/merging capabilities.

Eclipse/IDEA task types

Tasks contributed by IDE plugins. To configure IDE plugins please use IDE model types.

TypeDescription
GenerateEclipseProject

Generates an Eclipse .project file. If you want to fine tune the eclipse configuration

GenerateEclipseClasspath

Generates an Eclipse .classpath file. If you want to fine tune the eclipse configuration

GenerateEclipseJdt

Generates the Eclipse JDT configuration file. If you want to fine tune the eclipse configuration

GenerateEclipseWtpComponent

Generates the org.eclipse.wst.common.component settings file for Eclipse WTP. If you want to fine tune the eclipse configuration

GenerateEclipseWtpFacet

Generates the org.eclipse.wst.common.project.facet.core settings file for Eclipse WTP. If you want to fine tune the eclipse configuration

GenerateIdeaModule

Generates an IDEA module file. If you want to fine tune the idea configuration

GenerateIdeaProject

Generates an IDEA project file for root project *only*. If you want to fine tune the idea configuration

GenerateIdeaWorkspace

Generates an IDEA workspace file *only* for root project. There's little you can configure about workspace generation at the moment.