DependencyHandler

API Documentation:DependencyHandler

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

To declare a specific dependency for a configuration you can use the following syntax:

dependencies {
    configurationName dependencyNotation1, dependencyNotation2, ...
}

Example shows a basic way of declaring dependencies. 

apply plugin: 'java'
//so that we can use 'compile', 'testCompile' for dependencies

dependencies {
  //for dependencies found in artifact repositories you can use
  //the group:name:version notation
  compile 'commons-lang:commons-lang:2.6'
  testCompile 'org.mockito:mockito:1.9.0-rc1'

  //map-style notation:
  compile group: 'com.google.code.guice', name: 'guice', version: '1.0'

  //declaring arbitrary files as dependencies
  compile files('hibernate.jar', 'libs/spring.jar')

  //putting all jars from 'libs' onto compile classpath
  compile fileTree('libs')
}

Advanced dependency configuration

To do some advanced configuration on a dependency when it is declared, you can additionally pass a configuration closure:

dependencies {
    configurationName(dependencyNotation){
        configStatement1
        configStatement2
    }
}

Examples of advanced dependency declaration including:

  • Forcing certain dependency version in case of the conflict.
  • Excluding certain dependencies by name, group or both. More details about per-dependency exclusions can be found in docs for ModuleDependency.exclude().
  • Avoiding transitive dependencies for certain dependency.
apply plugin: 'java' //so that I can declare 'compile' dependencies

dependencies {
  compile('org.hibernate:hibernate:3.1') {
    //in case of versions conflict '3.1' version of hibernate wins:
    force = true

    //excluding a particular transitive dependency:
    exclude module: 'cglib' //by artifact name
    exclude group: 'org.jmock' //by group
    exclude group: 'org.unwanted', module: 'iAmBuggy' //by both name and group

    //disabling all transitive dependencies of this dependency
    transitive = false
  }
}

More examples of advanced configuration, useful when dependency module has multiple artifacts:

  • Declaring dependency to a specific configuration of the module.
  • Explicit specification of the artifact. See also ModuleDependency.artifact().
apply plugin: 'java' //so that I can declare 'compile' dependencies

dependencies {
  //configuring dependency to specific configuration of the module
  compile configuration: 'someConf', group: 'org.someOrg', name: 'someModule', version: '1.0'

  //configuring dependency on 'someLib' module
  compile(group: 'org.myorg', name: 'someLib', version:'1.0') {
    //explicitly adding the dependency artifact:
    artifact {
      //useful when some artifact properties unconventional
      name = 'someArtifact' //artifact name different than module name
      extension = 'someExt'
      type = 'someType'
      classifier = 'someClassifier'
    }
  }
}

Dependency notations

There are several supported dependency notations. These are described below. For each dependency declared this way, a Dependency object is created. You can use this object to query or further configure the dependency.

You can also always add instances of Dependency directly:

configurationName <instance>

External dependencies

There are two notations supported for declaring a dependency on an external module. One is a string notation formatted this way:

configurationName "group:name:version:classifier@extension"

The other is a map notation:

configurationName group: group:, name: name, version: version, classifier: classifier, ext: extension

In both notations, all properties, except name, are optional.

External dependencies are represented by a ExternalModuleDependency.

apply plugin: 'java'
//so that we can use 'compile', 'testCompile' for dependencies

dependencies {
  //for dependencies found in artifact repositories you can use
  //the string notation, e.g. group:name:version
  compile 'commons-lang:commons-lang:2.6'
  testCompile 'org.mockito:mockito:1.9.0-rc1'

  //map notation:
  compile group: 'com.google.code.guice', name: 'guice', version: '1.0'
}

Project dependencies

To add a project dependency, you use the following notation:

configurationName project(':someProject')

The notation project(':projectA') is similar to the syntax you use when configuring a projectA in a multi-module gradle project.

By default, when you declare dependency to projectA, you actually declare dependency to the 'default' configuration of the projectA. If you need to depend on a specific configuration of projectA, use map notation for projects:

configurationName project(path: ':projectA', configuration: 'someOtherConfiguration')

Project dependencies are represented using a ProjectDependency.

File dependencies

You can also add a dependency using a FileCollection:

configurationName files('a file') 

apply plugin: 'java'
//so that we can use 'compile', 'testCompile' for dependencies

dependencies {
  //declaring arbitrary files as dependencies
  compile files('hibernate.jar', 'libs/spring.jar')

  //putting all jars from 'libs' onto compile classpath
  compile fileTree('libs')
}

File dependencies are represented using a SelfResolvingDependency.

Dependencies to other configurations

You can add a dependency using a Configuration.

When the configuration is from the same project as the target configuration, the target configuration is changed to extend from the provided configuration.

When the configuration is from a different project, a project dependency is added.

Gradle distribution specific dependencies

It is possible to depend on certain Gradle APIs or libraries that Gradle ships with. It is particularly useful for Gradle plugin development. Example:

//Our Gradle plugin is written in groovy
apply plugin: 'groovy'
//now we can use the 'compile' configuration for declaring dependencies

dependencies {
  //we will use the Groovy version that ships with Gradle:
  compile localGroovy()

  //our plugin requires Gradle API interfaces and classes to compile:
  compile gradleApi()
}

Client module dependencies

To add a client module to a configuration you can use the notation:

configurationName module(moduleNotation) {
    module dependencies
}

The module notation is the same as the dependency notations described above, except that the classifier property is not available. Client modules are represented using a ClientModule.

Properties

PropertyDescription
components
Incubating

The component metadata handler for this project. The returned handler can be used for adding rules that modify the metadata of depended-on software components.

Methods

MethodDescription
add(configurationName, dependencyNotation)

Adds a dependency to the given configuration.

add(configurationName, dependencyNotation, configureClosure)

Adds a dependency to the given configuration, and configures the dependency using the given closure.

components(configureAction)
Incubating

Configures module metadata for this project.

create(dependencyNotation)

Creates a dependency without adding it to a configuration.

create(dependencyNotation, configureClosure)

Creates a dependency without adding it to a configuration, and configures the dependency using the given closure.

createArtifactResolutionQuery()
Incubating

Creates an artifact resolution query.

gradleApi()

Creates a dependency on the API of the current version of Gradle.

localGroovy()

Creates a dependency on the Groovy that is distributed with the current version of Gradle.

module(notation)

Creates a dependency on a client module.

module(notation, configureClosure)

Creates a dependency on a client module. The dependency is configured using the given closure before it is returned.

project(notation)

Creates a dependency on a project.

Script blocks

No script blocks

Property details

ComponentMetadataHandler components (read-only)

Note: This property is incubating and may change in a future version of Gradle.

The component metadata handler for this project. The returned handler can be used for adding rules that modify the metadata of depended-on software components.

Method details

Dependency add(String configurationName, Object dependencyNotation)

Adds a dependency to the given configuration.

Dependency add(String configurationName, Object dependencyNotation, Closure configureClosure)

Adds a dependency to the given configuration, and configures the dependency using the given closure.

void components(Action<? super ComponentMetadataHandler> configureAction)

Note: This method is incubating and may change in a future version of Gradle.

Configures module metadata for this project.

This method executes the given action against the ComponentMetadataHandler for this project.

Dependency create(Object dependencyNotation)

Creates a dependency without adding it to a configuration.

Dependency create(Object dependencyNotation, Closure configureClosure)

Creates a dependency without adding it to a configuration, and configures the dependency using the given closure.

ArtifactResolutionQuery createArtifactResolutionQuery()

Note: This method is incubating and may change in a future version of Gradle.

Creates an artifact resolution query.

Dependency gradleApi()

Creates a dependency on the API of the current version of Gradle.

Dependency localGroovy()

Creates a dependency on the Groovy that is distributed with the current version of Gradle.

Dependency module(Object notation)

Creates a dependency on a client module.

Dependency module(Object notation, Closure configureClosure)

Creates a dependency on a client module. The dependency is configured using the given closure before it is returned.

Dependency project(Map<String, ?> notation)

Creates a dependency on a project.