Gradle User Guide

A better way to build

Version 1.1

Hans Dockter

Adam Murdoch

Copyright © 2007-2012 Hans Dockter, Adam Murdoch

Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that each copy contains this Copyright Notice, whether distributed in print or electronically.

Table of Contents

1. Introduction

1.1. About this user guide

2. Overview

2.1. Features
2.2. Why Groovy?

3. Tutorials

3.1. Getting Started

4. Installing Gradle

4.1. Prerequisites
4.2. Download
4.3. Unpacking
4.4. Environment variables
4.5. Running and testing your installation
4.6. JVM options

5. Troubleshooting

5.1. Working through problems
5.2. Getting help

6. Build Script Basics

6.1. Projects and tasks
6.2. Hello world
6.3. A shortcut task definition
6.4. Build scripts are code
6.5. Task dependencies
6.6. Dynamic tasks
6.7. Manipulating existing tasks
6.8. Shortcut notations
6.9. Extra task properties
6.10. Using Ant Tasks
6.11. Using methods
6.12. Default tasks
6.13. Configure by DAG
6.14. Where to next?

7. Java Quickstart

7.1. The Java plugin
7.2. A basic Java project
7.3. Multi-project Java build
7.4. Where to next?

8. Dependency Management Basics

8.1. What is dependency management?
8.2. Declaring your dependencies
8.3. Dependency configurations
8.4. External dependencies
8.5. Repositories
8.6. Publishing artifacts
8.7. Where to next?

9. Groovy Quickstart

9.1. A basic Groovy project
9.2. Summary

10. Web Application Quickstart

10.1. Building a WAR file
10.2. Running your web application
10.3. Summary

11. Using the Gradle Command-Line

11.1. Executing multiple tasks
11.2. Excluding tasks
11.3. Task name abbreviation
11.4. Selecting which build to execute
11.5. Obtaining information about your build
11.6. Dry Run
11.7. Summary

12. Using the Gradle Graphical User Interface

12.1. Task Tree
12.2. Favorites
12.3. Command Line
12.4. Setup

13. Writing Build Scripts

13.1. The Gradle build language
13.2. The Project API
13.3. The Script API
13.4. Declaring variables
13.5. Some Groovy basics

14. Tutorial - 'This and That'

14.1. Directory creation
14.2. Gradle properties and system properties
14.3. Configuring the project using an external build script
14.4. Configuring arbitrary objects
14.5. Configuring arbitrary objects using an external script
14.6. Caching

15. More about Tasks

15.1. Defining tasks
15.2. Locating tasks
15.3. Configuring tasks
15.4. Adding dependencies to a task
15.5. Adding a description to a task
15.6. Replacing tasks
15.7. Skipping tasks
15.8. Skipping tasks that are up-to-date
15.9. Task rules
15.10. Summary

16. Working With Files

16.1. Locating files
16.2. File collections
16.3. File trees
16.4. Using the contents of an archive as a file tree
16.5. Specifying a set of input files
16.6. Copying files
16.7. Using the Sync task
16.8. Creating archives

17. Using Ant from Gradle

17.1. Using Ant tasks and types in your build
17.2. Importing an Ant build
17.3. Ant properties and references
17.4. API

18. Logging

18.1. Choosing a log level
18.2. Writing your own log messages
18.3. Logging from external tools and libraries
18.4. Changing what Gradle logs

19. The Gradle Daemon

19.1. Enter the daemon
19.2. Reusing and expiration of daemons
19.3. Usage and troubleshooting
19.4. Daemon properties

20. The Build Environment

20.1. Configuring the build environment via gradle.properties
20.2. Accessing the web via a proxy

21. Gradle Plugins

21.1. Applying plugins
21.2. What plugins do
21.3. Conventions
21.4. More on plugins

22. Standard Gradle plugins

22.1. Language plugins
22.2. Experimental language plugins
22.3. Integration plugins
22.4. Software development plugins
22.5. Base plugins
22.6. Third party plugins

23. The Java Plugin

23.1. Usage
23.2. Source sets
23.3. Tasks
23.4. Project layout
23.5. Dependency management
23.6. Convention properties
23.7. Working with source sets
23.8. Javadoc
23.9. Clean
23.10. Resources
23.11. CompileJava
23.12. Test
23.13. Jar
23.14. Uploading

24. The Groovy Plugin

24.1. Usage
24.2. Tasks
24.3. Project layout
24.4. Dependency management
24.5. Convention properties
24.6. Source set properties
24.7. CompileGroovy

25. The Scala Plugin

25.1. Usage
25.2. Tasks
25.3. Project layout
25.4. Dependency Management
25.5. Convention Properties
25.6. Source set properties
25.7. Fast Scala Compiler

26. The War Plugin

26.1. Usage
26.2. Tasks
26.3. Project layout
26.4. Dependency management
26.5. Convention properties
26.6. War
26.7. Customizing

27. The Ear Plugin

27.1. Usage
27.2. Tasks
27.3. Project layout
27.4. Dependency management
27.5. Convention properties
27.6. Ear
27.7. Customizing
27.8. Using custom descriptor file

28. The Jetty Plugin

28.1. Usage
28.2. Tasks
28.3. Project layout
28.4. Dependency management
28.5. Convention properties

29. The Checkstyle Plugin

29.1. Usage
29.2. Tasks
29.3. Project layout
29.4. Dependency management
29.5. Configuration

30. The CodeNarc Plugin

30.1. Usage
30.2. Tasks
30.3. Project layout
30.4. Dependency management
30.5. Configuration

31. The FindBugs Plugin

31.1. Usage
31.2. Tasks
31.3. Dependency management
31.4. Configuration

32. The JDepend Plugin

32.1. Usage
32.2. Tasks
32.3. Dependency management
32.4. Configuration

33. The PMD Plugin

33.1. Usage
33.2. Tasks
33.3. Dependency management
33.4. Configuration

34. The Sonar Plugin

34.1. Usage
34.2. Analyzing Multi-Project Builds
34.3. Analyzing Custom Source Sets
34.4. Setting Custom Sonar Properties
34.5. Tasks

35. The OSGi Plugin

35.1. Usage
35.2. Implicitly applied plugins
35.3. Tasks
35.4. Dependency management
35.5. Convention object
35.6.

36. The Eclipse Plugin

36.1. Usage
36.2. Tasks
36.3. Configuration
36.4. Customizing the generated files

37. The IDEA Plugin

37.1. Usage
37.2. Tasks
37.3. Configuration
37.4. Customizing the generated files
37.5. Further things to consider

38. The Antlr Plugin

38.1. Usage
38.2. Tasks
38.3. Project layout
38.4. Dependency management
38.5. Convention properties
38.6. Source set properties

39. The Project Report Plugin

39.1. Usage
39.2. Tasks
39.3. Project layout
39.4. Dependency management
39.5. Convention properties

40. The Announce Plugin

40.1. Usage
40.2. Configuration

41. The Build Announcements Plugin

41.1. Usage

42. The Application Plugin

42.1. Usage
42.2. Tasks
42.3. Convention properties
42.4. Including other resources in the distribution

43. Dependency Management

43.1. Introduction
43.2. Dependency management overview
43.3. Dependency configurations
43.4. How to declare your dependencies
43.5. Working with dependencies
43.6. Repositories
43.7. How dependency resolution works
43.8. The dependency cache
43.9. Strategies for transitive dependency management

44. Publishing artifacts

44.1. Introduction
44.2. Artifacts and configurations
44.3. Declaring artifacts
44.4. Publishing artifacts
44.5. More about project libraries

45. The Maven Plugin

45.1. Usage
45.2. Tasks
45.3. Dependency management
45.4. Convention properties
45.5. Convention methods
45.6. Interacting with Maven repositories

46. The Signing Plugin

46.1. Usage
46.2. Signatory credentials
46.3. Specifying what to sign
46.4. Publishing the signatures
46.5. Signing POM files

47. C++ Support

47.1. Usage
47.2. Source code locations
47.3. Compiling
47.4. Configuring the compiler
47.5. Working with shared libraries
47.6. Dependencies
47.7. Publishing

48. The Build Lifecycle

48.1. Build phases
48.2. Settings file
48.3. Multi-project builds
48.4. Initialization
48.5. Configuration and execution of a single project build
48.6. Responding to the lifecycle in the build script

49. Multi-project Builds

49.1. Cross project configuration
49.2. Subproject configuration
49.3. Execution rules for multi-project builds
49.4. Running tasks by their absolute path
49.5. Project and task paths
49.6. Dependencies - Which dependencies?
49.7. Project lib dependencies
49.8. Multi-Project Building and Testing
49.9. Property and method inheritance
49.10. Summary

50. Writing Custom Task Classes

50.1. Packaging a task class
50.2. Writing a simple task class
50.3. A standalone project

51. Writing Custom Plugins

51.1. Packaging a plugin
51.2. Writing a simple plugin
51.3. Getting input from the build
51.4. Working with files in custom tasks and plugins
51.5. A standalone project
51.6. Maintaining multiple domain objects

52. Organizing Build Logic

52.1. Inherited properties and methods
52.2. Injected configuration
52.3. Build sources in the buildSrc project
52.4. Running another Gradle build from a build
52.5. External dependencies for the build script
52.6. Ant optional dependencies
52.7. Summary

53. Initialization Scripts

53.1. Basic usage
53.2. Using an init script
53.3. Writing an init script
53.4. External dependencies for the init script

54. The Gradle Wrapper

54.1. Configuration
54.2. Unix file permissions
54.3. Environment variable

55. Embedding Gradle

55.1. Introduction to the Tooling API
55.2. Tooling API and the Gradle Build Daemon
55.3. Quickstart

A. Gradle Samples

A.1. Sample customBuildLanguage
A.2. Sample customDistribution
A.3. Sample customPlugin
A.4. Sample java/multiproject

B. Potential Traps

B.1. Groovy script variables
B.2. Configuration and execution phase

C. Gradle Command Line

C.1. Deprecated command-line options
C.2. Daemon command-line options:
C.3. System properties
C.4. Environment variables

D. Existing IDE Support and how to cope without it

D.1. IntelliJ
D.2. Eclipse
D.3. Using Gradle without IDE support

List of Examples

6.1. The first build script
6.2. Execution of a build script
6.3. A task definition shortcut
6.4. Using Groovy in Gradle's tasks
6.5. Using Groovy in Gradle's tasks
6.6. Declaration of dependencies between tasks
6.7. Lazy dependsOn - the other task does not exist (yet)
6.8. Dynamic creation of a task
6.9. Accessing a task via API - adding a dependency
6.10. Accessing a task via API - adding behaviour
6.11. Accessing task as a property of the build script
6.12. Adding extra properties to a task
6.13. Using AntBuilder to execute ant.loadfile target
6.14. Using methods to organize your build logic
6.15. Defining a default tasks
6.16. Different outcomes of build depending on chosen tasks
7.1. Using the Java plugin
7.2. Building a Java project
7.3. Adding Maven repository
7.4. Adding dependencies
7.5. Customization of MANIFEST.MF
7.6. Adding a test system property
7.7. Publishing the JAR file
7.8. Eclipse plugin
7.9. Java example - complete build file
7.10. Multi-project build - hierarchical layout
7.11. Multi-project build - settings.gradle file
7.12. Multi-project build - common configuration
7.13. Multi-project build - dependencies between projects
7.14. Multi-project build - distribution file
8.1. Declaring dependencies
8.2. Definition of an external dependency
8.3. Shortcut definition of an external dependency
8.4. Usage of Maven central repository
8.5. Usage of a remote Maven repository
8.6. Usage of a remote Ivy directory
8.7. Usage of a local Ivy directory
8.8. Publishing to an Ivy repository
8.9. Publishing to a Maven repository
9.1. Groovy plugin
9.2. Dependency on Groovy 1.7.10
9.3. Groovy example - complete build file
10.1. War plugin
10.2. Running web application with Jetty plugin
11.1. Executing multiple tasks
11.2. Excluding tasks
11.3. Abbreviated task name
11.4. Abbreviated camel case task name
11.5. Selecting the project using a build file
11.6. Selecting the project using project directory
11.7. Obtaining information about projects
11.8. Providing a description for a project
11.9. Obtaining information about tasks
11.10. Changing the content of the task report
11.11. Obtaining more information about tasks
11.12. Obtaining information about dependencies
11.13. Information about properties
12.1. Launching the GUI
13.1. Accessing property of the Project object
13.2. Using local variables
13.3. Using extra properties
13.4. Groovy JDK methods
13.5. Property accessors
13.6. Method call without parentheses
13.7. List and map literals
13.8. Closure as method parameter
13.9. Closure delegates
14.1. Directory creation with mkdir
14.2. Setting properties with a gradle.properties file
14.3. Configuring the project using an external build script
14.4. Configuring arbitrary objects
14.5. Configuring arbitrary objects using a script
15.1. Defining tasks
15.2. Defining tasks - using strings
15.3. Defining tasks with alternative syntax
15.4. Accessing tasks as properties
15.5. Accessing tasks via tasks collection
15.6. Accessing tasks by path
15.7. Creating a copy task
15.8. Configuring a task - various ways
15.9. Configuring a task - fluent interface
15.10. Configuring a task - with closure
15.11. Configuring a task - with configure() method
15.12. Defining a task with closure
15.13. Adding dependency on task from another project
15.14. Adding dependency using task object
15.15. Adding dependency using closure
15.16. Adding a description to a task
15.17. Overwriting a task
15.18. Skipping a task using a predicate
15.19. Skipping tasks with StopExecutionException
15.20. Enabling and disabling tasks
15.21. A generator task
15.22. Declaring the inputs and outputs of a task
15.23. Task rule
15.24. Dependency on rule based tasks
16.1. Locating files
16.2. Creating a file collection
16.3. Using a file collection
16.4. Implementing a file collection
16.5. Creating a file tree
16.6. Using a file tree
16.7. Using an archive as a file tree
16.8. Specifying a set of files
16.9. Specifying a set of files
16.10. Copying files using the copy task
16.11. Specifying copy task source files and destination directory
16.12. Selecting the files to copy
16.13. Copying files using the copy() method
16.14. Renaming files as they are copied
16.15. Filtering files as they are copied
16.16. Nested copy specs
16.17. Using the Sync task to copy dependencies
16.18. Creating a ZIP archive
16.19. Creation of ZIP archive
16.20. Configuration of archive task - custom archive name
16.21. Configuration of archive task - appendix & classifier
17.1. Using an Ant task
17.2. Passing nested text to an Ant task
17.3. Passing nested elements to an Ant task
17.4. Using an Ant type
17.5. Using a custom Ant task
17.6. Declaring the classpath for a custom Ant task
17.7. Using a custom Ant task and dependency management together
17.8. Importing an Ant build
17.9. Task that depends on Ant target
17.10. Adding behaviour to an Ant target
17.11. Ant target that depends on Gradle task
17.12. Setting an Ant property
17.13. Getting an Ant property
17.14. Setting an Ant reference
17.15. Getting an Ant reference
18.1. Using stdout to write log messages
18.2. Writing your own log messages
18.3. Using SLF4J to write log messages
18.4. Configuring standard output capture
18.5. Configuring standard output capture for a task
18.6. Customizing what Gradle logs
20.1. Configuring an HTTP proxy
20.2. Configuring an HTTPS proxy
21.1. Applying a plugin
21.2. Applying a plugin by type
21.3. Applying a plugin by type
21.4. Tasks added by a plugin
21.5. Changing plugin defaults
21.6. Plugin convention object
23.1. Using the Java plugin
23.2. Custom Java source layout
23.3. Accessing a source set
23.4. Configuring the source directories of a source set
23.5. Defining a source set
23.6. Defining source set dependencies
23.7. Compiling a source set
23.8. Assembling a JAR for a source set
23.9. Generating the Javadoc for a source set
23.10. Running tests in a source set
23.11. Customization of MANIFEST.MF
23.12. Creating a manifest object.
23.13. Separate MANIFEST.MF for a particular archive
23.14. Separate MANIFEST.MF for a particular archive
24.1. Using the Groovy plugin
24.2. Custom Groovy source layout
24.3. Configuration of Groovy plugin
24.4. Configuration of Groovy plugin
25.1. Using the Scala plugin
25.2. Custom Scala source layout
25.3. Declaring the Scala version to use
25.4. Enabling the Fast Scala Compiler
26.1. Using the War plugin
26.2. Customization of war plugin
27.1. Using the Ear plugin
27.2. Customization of ear plugin
28.1. Using the Jetty plugin
29.1. Using the Checkstyle plugin
30.1. Using the CodeNarc plugin
31.1. Using the FindBugs plugin
32.1. Using the JDepend plugin
33.1. Using the PMD plugin
34.1. Applying the Sonar plugin
34.2. Configuring Sonar connection settings
34.3. Configuring Sonar project settings
34.4. Global configuration in a multi-project build
34.5. Common project configuration in a multi-project build
34.6. Individual project configuration in a multi-project build
34.7. Configuring the language to be analyzed
34.8. Using property syntax
34.9. Analyzing custom source sets
34.10. Setting custom global properties
34.11. Setting custom project properties
35.1. Using the OSGi plugin
35.2. Configuration of OSGi MANIFEST.MF file
36.1. Using the Eclipse plugin
36.2. Partial Overwrite for Classpath
36.3. Partial Overwrite for Project
36.4. Export Dependencies
36.5. Customizing the XML
37.1. Using the IDEA plugin
37.2. Partial Overwrite for Module
37.3. Partial Overwrite for Project
37.4. Export Dependencies
37.5. Customizing the XML
38.1. Using the Antlr plugin
38.2. Declare Antlr version
40.1. Using the announce plugin
40.2. Configure the announce plugin
40.3. Using the announce plugin
41.1. Using the build announcements plugin
41.2. Using the build announcements plugin from an init script
42.1. Using the application plugin
42.2. Configure the application main class
42.3. Include output from other tasks in the application distribution
42.4. Automatically creating files for distribution
43.1. Definition of a configuration
43.2. Accessing a configuration
43.3. Configuration of a configuration
43.4. Module dependencies
43.5. Artifact only notation
43.6. Dependency with classifier
43.7. Usage of external dependency of a configuration
43.8. Client module dependencies - transitive dependencies
43.9. Project dependencies
43.10. File dependencies
43.11. Generated file dependencies
43.12. Gradle API dependencies
43.13. Gradle's Groovy dependencies
43.14. Excluding transitive dependencies
43.15. Optional attributes of dependencies
43.16. Collections and arrays of dependencies
43.17. Dependency configurations
43.18. Dependency configurations for project
43.19. Configuration.copy
43.20. Accessing declared dependencies
43.21. Configuration.files
43.22. Configuration.files with spec
43.23. Configuration.copy
43.24. Configuration.copy vs. Configuration.files
43.25. Adding central Maven repository
43.26. Adding the local Maven cache as a repository
43.27. Adding custom Maven repository
43.28. Adding additional Maven repositories for JAR files
43.29. Accessing password protected Maven repository
43.30. Flat repository resolver
43.31. Ivy repository
43.32. Ivy repository with pattern layout
43.33. Ivy repository with custom patterns
43.34. Ivy repository
43.35. Accessing a repository
43.36. Configuration of a repository
43.37. Definition of a custom repository
43.38. Dynamic version cache control
43.39. Changing module cache control
44.1. Defining an artifact using an archive task
44.2. Defining an artifact using a file
44.3. Customizing an artifact
44.4. Map syntax for defining an artifact using a file
44.5. Configuration of the upload task
45.1. Using the Maven plugin
45.2. Creating a stand alone pom.
45.3. Upload of file to remote Maven repository
45.4. Upload of file via SSH
45.5. Customization of pom
45.6. Builder style customization of pom
45.7. Modifying auto-generated content
45.8. Customization of Maven installer
45.9. Generation of multiple poms
45.10. Accessing a mapping configuration
46.1. Using the Signing plugin
46.2. Signing a configuration
46.3. Signing a configuration output
46.4. Signing a task
46.5. Signing a task output
46.6. Conditional signing
46.7. Signing a POM for deployment
47.1. Using the 'cpp-exe' plugin
47.2. Using the 'cpp-lib' plugin
47.3. Supplying arbitrary args to the compiler
47.4. Declaring dependencies
47.5. Declaring project dependencies
47.6. Uploading exe or lib
48.1. Single project build
48.2. Hierarchical layout
48.3. Flat layout
48.4. Modification of elements of the project tree
48.5. Modification of elements of the project tree
48.6. Adding of test task to each project which has certain property set
48.7. Notifications
48.8. Setting of certain property to all tasks
48.9. Logging of start and end of each task execution
49.1. Multi-project tree - water & bluewhale projects
49.2. Build script of water (parent) project
49.3. Multi-project tree - water, bluewhale & krill projects
49.4. Water project build script
49.5. Defining common behaviour of all projects and subprojects
49.6. Defining specific behaviour for particular project
49.7. Defining specific behaviour for project krill
49.8. Adding custom behaviour to some projects (filtered by project name)
49.9. Adding custom behaviour to some projects (filtered by project properties)
49.10. Running build from subproject
49.11. Evaluation and execution of projects
49.12. Evaluation and execution of projects
49.13. Running tasks by their absolute path
49.14. Dependencies and execution order
49.15. Dependencies and execution order
49.16. Dependencies and execution order
49.17. Declaring dependencies
49.18. Declaring dependencies
49.19. Cross project task dependencies
49.20. Configuration time dependencies
49.21. Configuration time dependencies - evaluationDependsOn
49.22. Configuration time dependencies
49.23. Dependencies - real life example - crossproject configuration
49.24. Project lib dependencies
49.25. Project lib dependencies
49.26. Fine grained control over dependencies
49.27. Build and Test Single Project
49.28. Partial Build and Test Single Project
49.29. Build and Test Depended On Projects
49.30. Build and Test Dependent Projects
50.1. Defining a custom task
50.2. A hello world task
50.3. A customizable hello world task
50.4. A build for a custom task
50.5. A custom task
50.6. Using a custom task in another project
50.7. Testing a custom task
51.1. A custom plugin
51.2. A custom plugin extension
51.3. A custom plugin with configuration closure
51.4. Evaluating file properties lazily
51.5. A build for a custom plugin
51.6. Wiring for a custom plugin
51.7. Using a custom plugin in another project
51.8. Testing a custom plugin
51.9. Managing domain objects
52.1. Using inherited properties and methods
52.2. Using injected properties and methods
52.3. Custom buildSrc build script
52.4. Adding subprojects to the root buildSrc project
52.5. Running another build from a build
52.6. Declaring external dependencies for the build script
52.7. A build script with external dependencies
52.8. Ant optional dependencies
53.1. Using init script to perform extra configuration before projects are evaluated
53.2. Declaring external dependencies for an init script
53.3. An init script with external dependencies
54.1. Wrapper task
54.2. Wrapper generated files
54.3. Configuration of wrapper task
B.1. Variables scope: local and script wide
B.2. Distinct configuration and execution phase