# Interface DependencyHandler

All Superinterfaces:
  `ExtensionAware`

@ServiceScope(org.gradle.internal.service.scopes.Scope.Project.class) public interface DependencyHandler extends ExtensionAware

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(dependencyNotation)
    }

Example shows a basic way of declaring dependencies.

    plugins {
        id("java-library")
    }

    dependencies {
        // Declare dependency on module components
        // Coordinates are separated by a single colon -- group:name:version
        implementation("org.apache.commons:commons-lang3:3.17.0")
        testImplementation("org.mockito:mockito-core:5.18.0")

        // Declare dependency on arbitrary files
        implementation(files("hibernate.jar", "libs/spring.jar"))

        // Declare dependency on all jars from the 'libs' directory
        implementation(fileTree("libs"))
    }

## Advanced dependency configuration

To perform advanced configuration on a dependency when it is declared, you can pass an additional configuration closure:

    dependencies {
        configurationName(dependencyNotation){
            configStatement1
            configStatement2
        }
    }

Examples of advanced dependency declaration include:

- 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(java.util.Map)`.
- Avoiding transitive dependencies for certain dependency.

    plugins {
        id("java-library")
    }

    dependencies {
        implementation('org.hibernate:hibernate') {
            // In case of versions conflict '3.1' version of hibernate wins:
            version {
                strictly('3.1')
            }

            // 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
        }
    }

Below are more examples of advanced configuration, which may be useful when a target component has multiple artifacts:

- Declaring dependency on a specific configuration of the component.
- Declaring explicit artifact requests. See also `ModuleDependency.artifact(groovy.lang.Closure)`.

    plugins {
        id("java-library")
    }

    dependencies {
        // Configuring dependency to specific configuration of the module
        // This notation should _only_ be used for Ivy dependencies
        implementation("org.someOrg:someModule:1.0") {
            targetConfiguration = "someConf"
        }

        // Configuring dependency on 'someLib' module
        implementation("org.myorg:someLib:1.0") {
            // Explicitly adding the dependency artifact:
            // Prefer variant-aware dependency resolution
            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>)`

Dependencies can also be declared with a `Provider` that provides any of the other supported dependency notations.

### External dependencies

The following notation is used to declare a dependency on an external module:

`configurationName("group:name:version:classifier@extension")`

All properties, except name, are optional.

External dependencies are represented by a `ExternalModuleDependency`.

    plugins {
        id("java-library")
    }

    dependencies {
        // Declare dependency on module components
        // Coordinates are separated by a single colon -- group:name:version
        implementation("org.apache.commons:commons-lang3:3.17.0")
        testImplementation("org.mockito:mockito-core:5.18.0")
    }

### Project dependencies

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

`configurationName(project(":some-project"))`

Project dependencies are resolved by treating each consumable configuration in the target project as a variant and performing variant-aware attribute matching against them. However, in order to override this process, an explicit target configuration can be specified:

`configurationName(project(path: ":project-a", configuration: "someOtherConfiguration"))`

Project dependencies are represented using a `ProjectDependency`.

### File dependencies

You can also add a dependency using a `FileCollection`:

`configurationName(files("a file"))`

    plugins {
        id("java-library")
    }

    dependencies {
        // Declare dependency on arbitrary files
        implementation(files("hibernate.jar", "libs/spring.jar"))

        // Declare dependency on all jars from the 'libs' directory
        implementation(fileTree("libs"))
    }

File dependencies are represented using a `FileCollectionDependency`.

### 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:

    plugins {
        id("groovy")
    }

    dependencies {
        // Declare dependency on the Groovy version that ships with Gradle
        implementation(localGroovy())

        // Declare dependency on the Gradle API interfaces and classes
        implementation(gradleApi())

        // Declare dependency on the Gradle test-kit to test build logic
        testImplementation(gradleTestKit())
    }

- ## Method Summary

  Modifier and Type
  Method
  Description
  `@Nullable Dependency`
  `add(String configurationName, Object dependencyNotation)`
  Adds a dependency to the given configuration.
  `@Nullable Dependency`
  `add(String configurationName, Object dependencyNotation, Closure configureClosure)`
  Adds a dependency to the given configuration, and configures the dependency using the given closure.
  `<T> void`
  `addProvider(String configurationName, Provider<T> dependencyNotation)`
  Adds a dependency provider to the given configuration.
  `<T, U extends ExternalModuleDependency>
  void`
  `addProvider(String configurationName, Provider<T> dependencyNotation, Action<? super U> configuration)`
  Adds a dependency provider to the given configuration, eventually configures the dependency using the given action.
  `<T> void`
  `addProviderConvertible(String configurationName, ProviderConvertible<T> dependencyNotation)`
  Adds a dependency provider to the given configuration.
  `<T, U extends ExternalModuleDependency>
  void`
  `addProviderConvertible(String configurationName, ProviderConvertible<T> dependencyNotation, Action<? super U> configuration)`
  Adds a dependency provider to the given configuration, eventually configures the dependency using the given action.
  `void`
  `artifactTypes(Action<? super ArtifactTypeContainer> configureAction)`
  Configures the artifact type definitions for this handler.
  `AttributesSchema`
  `attributesSchema(Action<? super AttributesSchema> configureAction)`
  Configures the attributes schema.
  `void`
  `components(Action<? super ComponentMetadataHandler> configureAction)`
  Configures component metadata for this project.
  `void`
  `constraints(Action<? super DependencyConstraintHandler> configureAction)`
  Configures dependency constraint 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()`
  Creates an artifact resolution query.
  `Dependency`
  `enforcedPlatform(Object notation)`
  Declares a dependency on an enforced platform.
  `Dependency`
  `enforcedPlatform(Object notation, Action<? super Dependency> configureAction)`
  Declares a dependency on an enforced platform.
  `Provider<MinimalExternalModuleDependency>`
  `enforcedPlatform(Provider<MinimalExternalModuleDependency> dependencyProvider)`
  Configures this dependency provider to select the enforced-platform variant of the target component
  `default Provider<MinimalExternalModuleDependency>`
  `enforcedPlatform(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible)`
  Configures this dependency provider to select the enforced-platform variant of the target component
  `ArtifactTypeContainer`
  `getArtifactTypes()`
  Returns the artifact type definitions for this handler.
  `AttributesSchema`
  `getAttributesSchema()`
  Returns the attributes schema for this handler.
  `ComponentMetadataHandler`
  `getComponents()`
  Returns the component metadata handler for this project.
  `DependencyConstraintHandler`
  `getConstraints()`
  Returns the dependency constraint handler for this project.
  `ComponentModuleMetadataHandler`
  `getModules()`
  Returns the component module metadata handler for this project.
  `Dependency`
  `gradleApi()`
  Creates a dependency on the API of the current version of Gradle.
  `Dependency`
  `gradleTestKit()`
  Creates a dependency on the Gradle test-kit API.
  `Dependency`
  `localGroovy()`
  Creates a dependency on the Groovy that is distributed with the current version of Gradle.
  `void`
  `modules(Action<? super ComponentModuleMetadataHandler> configureAction)`
  Configures module metadata for this project.
  `Dependency`
  `platform(Object notation)`
  Declares a dependency on a platform.
  `Dependency`
  `platform(Object notation, Action<? super Dependency> configureAction)`
  Declares a dependency on a platform.
  `default Provider<MinimalExternalModuleDependency>`
  `platform(Provider<MinimalExternalModuleDependency> dependencyProvider)`
  Configures this dependency provider to select the platform variant of the target component
  `default Provider<MinimalExternalModuleDependency>`
  `platform(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible)`
  Configures this dependency provider to select the platform variant of the target component
  `ProjectDependency`
  `project()`
  Creates a dependency on the current project.
  `ProjectDependency`
  `project(String projectPath)`
  Creates a dependency on a project by path.
  `Dependency`
  `project(Map<String,?> notation)`
  Creates a dependency on a project.
  `<T extends TransformParameters>
  void`
  `registerTransform(Class<? extends TransformAction<T>> actionType, Action<? super TransformSpec<T>> registrationAction)`
  Registers an artifact transform.
  `Dependency`
  `testFixtures(Object notation)`
  Declares a dependency on the test fixtures of a component.
  `Dependency`
  `testFixtures(Object notation, Action<? super Dependency> configureAction)`
  Declares a dependency on the test fixtures of a component and allows configuring the resulting dependency.
  `default Provider<MinimalExternalModuleDependency>`
  `testFixtures(Provider<MinimalExternalModuleDependency> dependencyProvider)`
  Configures this dependency provider to select the test fixtures of the target component
  `default Provider<MinimalExternalModuleDependency>`
  `testFixtures(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible)`
  Configures this dependency provider to select the test fixtures of the target component
  `Provider<MinimalExternalModuleDependency>`
  `variantOf(Provider<MinimalExternalModuleDependency> dependencyProvider, Action<? super ExternalModuleDependencyVariantSpec> variantSpec)`
  Allows fine-tuning what variant to select for the target dependency.
  `default Provider<MinimalExternalModuleDependency>`
  `variantOf(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible, Action<? super ExternalModuleDependencyVariantSpec> variantSpec)`
  Allows fine-tuning what variant to select for the target dependency.

  ### Methods inherited from interface ExtensionAware

  `getExtensions`

- ## Method Details

  - ### add

    @Nullable Dependency add(String configurationName, Object dependencyNotation)
    Adds a dependency to the given configuration.
    Parameters:
      `configurationName` - The name of the configuration.
      `dependencyNotation` - The dependency notation, in one of the notations described above.
    Returns:
      The dependency, or null if dependencyNotation is a provider.

  - ### add

    @Nullable Dependency add(String configurationName, Object dependencyNotation, Closure configureClosure)
    Adds a dependency to the given configuration, and configures the dependency using the given closure.
    Parameters:
      `configurationName` - The name of the configuration.
      `dependencyNotation` - The dependency notation, in one of the notations described above.
      `configureClosure` - The closure to use to configure the dependency.
    Returns:
      The dependency, or null if dependencyNotation is a provider.

  - ### addProvider

    <T, U extends ExternalModuleDependency> void addProvider(String configurationName, Provider<T> dependencyNotation, Action<? super U> configuration)
    Adds a dependency provider to the given configuration, eventually configures the dependency using the given action.
    Parameters:
      `configurationName` - The name of the configuration.
      `dependencyNotation` - The dependency provider notation, in one of the notations described above.
      `configuration` - The action to use to configure the dependency.
    Since:
      6.8

  - ### addProvider

    <T> void addProvider(String configurationName, Provider<T> dependencyNotation)
    Adds a dependency provider to the given configuration.
    Parameters:
      `configurationName` - The name of the configuration.
      `dependencyNotation` - The dependency provider notation, in one of the notations described above.
    Since:
      7.0

  - ### addProviderConvertible

    <T, U extends ExternalModuleDependency> void addProviderConvertible(String configurationName, ProviderConvertible<T> dependencyNotation, Action<? super U> configuration)
    Adds a dependency provider to the given configuration, eventually configures the dependency using the given action.
    Parameters:
      `configurationName` - The name of the configuration.
      `dependencyNotation` - The dependency provider notation, in one of the notations described above.
      `configuration` - The action to use to configure the dependency.
    Since:
      7.4

  - ### addProviderConvertible

    <T> void addProviderConvertible(String configurationName, ProviderConvertible<T> dependencyNotation)
    Adds a dependency provider to the given configuration.
    Parameters:
      `configurationName` - The name of the configuration.
      `dependencyNotation` - The dependency provider notation, in one of the notations described above.
    Since:
      7.4

  - ### create

    Dependency create(Object dependencyNotation)
    Creates a dependency without adding it to a configuration.
    Parameters:
      `dependencyNotation` - The dependency notation, in one of the notations described above.
    Returns:
      The dependency.

  - ### create

    Dependency create(Object dependencyNotation, Closure configureClosure)
    Creates a dependency without adding it to a configuration, and configures the dependency using the given closure.
    Parameters:
      `dependencyNotation` - The dependency notation, in one of the notations described above.
      `configureClosure` - The closure to use to configure the dependency.
    Returns:
      The dependency.

  - ### project

    Dependency project(Map<String,?> notation)
    Creates a dependency on a project.
    Parameters:
      `notation` - The project notation, in one of the notations described above.
    Returns:
      The dependency.

  - ### project

    ProjectDependency project()
    Creates a dependency on the current project.
    Returns:
      The dependency.
    Since:
      9.5.0

  - ### project

    ProjectDependency project(String projectPath)
    Creates a dependency on a project by path.
    Parameters:
      `projectPath` - the path of the project, e.g. ":sub-project"
    Returns:
      The dependency.
    Since:
      9.5.0
    See Also:
      - `Project.getPath()`

  - ### gradleApi

    Dependency gradleApi()
    Creates a dependency on the API of the current version of Gradle.
    Returns:
      The dependency.

  - ### gradleTestKit

    Dependency gradleTestKit()
    Creates a dependency on the Gradle test-kit API.
    Returns:
      The dependency.
    Since:
      2.6

  - ### localGroovy

    Dependency localGroovy()
    Creates a dependency on the Groovy that is distributed with the current version of Gradle.
    Returns:
      The dependency.

  - ### getConstraints

    DependencyConstraintHandler getConstraints()
    Returns the dependency constraint handler for this project.
    Returns:
      the dependency constraint handler for this project
    Since:
      4.5

  - ### constraints

    void constraints(Action<? super DependencyConstraintHandler> configureAction)
    Configures dependency constraint for this project.

    This method executes the given action against the `DependencyConstraintHandler` for this project.

    Parameters:
      `configureAction` - the action to use to configure module metadata
    Since:
      4.5

  - ### getComponents

    ComponentMetadataHandler getComponents()
    Returns 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.
    Returns:
      the component metadata handler for this project
    Since:
      1.8

  - ### components

    void components(Action<? super ComponentMetadataHandler> configureAction)
    Configures component metadata for this project.

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

    Parameters:
      `configureAction` - the action to use to configure module metadata
    Since:
      1.8

  - ### getModules

    ComponentModuleMetadataHandler getModules()
    Returns the component module metadata handler for this project. The returned handler can be used for adding rules that modify the metadata of depended-on software components.
    Returns:
      the component module metadata handler for this project
    Since:
      2.2

  - ### modules

    void modules(Action<? super ComponentModuleMetadataHandler> configureAction)
    Configures module metadata for this project.

    This method executes the given action against the `ComponentModuleMetadataHandler` for this project.

    Parameters:
      `configureAction` - the action to use to configure module metadata
    Since:
      2.2

  - ### createArtifactResolutionQuery

    ArtifactResolutionQuery createArtifactResolutionQuery()
    Creates an artifact resolution query.

    This is a legacy API and is in maintenance mode. In future versions of Gradle, this API will be deprecated and removed. New code should not use this API. Prefer `ArtifactView.ViewConfiguration.withVariantReselection()` for resolving sources and javadoc.

    Since:
      2.0

  - ### attributesSchema

    AttributesSchema attributesSchema(Action<? super AttributesSchema> configureAction)
    Configures the attributes schema. The action is passed a `AttributesSchema` instance.
    Parameters:
      `configureAction` - the configure action
    Returns:
      the configured schema
    Since:
      3.4

  - ### getAttributesSchema

    AttributesSchema getAttributesSchema()
    Returns the attributes schema for this handler.
    Returns:
      the attributes schema
    Since:
      3.4

  - ### getArtifactTypes

    ArtifactTypeContainer getArtifactTypes()
    Returns the artifact type definitions for this handler.
    Since:
      4.0

  - ### artifactTypes

    void artifactTypes(Action<? super ArtifactTypeContainer> configureAction)
    Configures the artifact type definitions for this handler.
    Since:
      4.0

  - ### registerTransform

    <T extends TransformParameters> void registerTransform(Class<? extends TransformAction<T>> actionType, Action<? super TransformSpec<T>> registrationAction)
    Registers an artifact transform.

    The registration action needs to specify the `from` and `to` attributes. It may also provide parameters for the transform action by using `TransformSpec.parameters(Action)`.

    For example:

        // You have a transform action like this:
        abstract class MyTransform implements TransformAction<Parameters> {
            interface Parameters extends TransformParameters {
                @Input
                Property<String> getStringParameter();
                @InputFiles
                ConfigurableFileCollection getInputFiles();
            }

            void transform(TransformOutputs outputs) {
                // ...
            }
        }

        // Then you can register the action like this:

        def artifactType = Attribute.of('artifactType', String)

        dependencies.registerTransform(MyTransform) {
            from.attribute(artifactType, "jar")
            to.attribute(artifactType, "java-classes-directory")

            parameters {
                stringParameter.set("Some string")
                inputFiles.from("my-input-file")
            }
        }

    Since:
      5.3
    See Also:
      - `TransformAction`

  - ### platform

    Dependency platform(Object notation)
    Declares a dependency on a platform. If the target coordinates represent multiple potential components, the platform component will be selected, instead of the library.
    Parameters:
      `notation` - the coordinates of the platform
    Since:
      5.0

  - ### platform

    Dependency platform(Object notation, Action<? super Dependency> configureAction)
    Declares a dependency on a platform. If the target coordinates represent multiple potential components, the platform component will be selected, instead of the library.
    Parameters:
      `notation` - the coordinates of the platform
      `configureAction` - the dependency configuration block
    Since:
      5.0

  - ### enforcedPlatform

    Dependency enforcedPlatform(Object notation)
    Declares a dependency on an enforced platform. If the target coordinates represent multiple potential components, the platform component will be selected, instead of the library. An enforced platform is a platform for which the direct dependencies are forced, meaning that they would override any other version found in the graph.
    Parameters:
      `notation` - the coordinates of the platform
    Since:
      5.0

  - ### enforcedPlatform

    Dependency enforcedPlatform(Object notation, Action<? super Dependency> configureAction)
    Declares a dependency on an enforced platform. If the target coordinates represent multiple potential components, the platform component will be selected, instead of the library. An enforced platform is a platform for which the direct dependencies are forced, meaning that they would override any other version found in the graph.
    Parameters:
      `notation` - the coordinates of the platform
      `configureAction` - the dependency configuration block
    Since:
      5.0

  - ### testFixtures

    Dependency testFixtures(Object notation)
    Declares a dependency on the test fixtures of a component.
    Parameters:
      `notation` - the coordinates of the component to use test fixtures for
    Since:
      5.6

  - ### testFixtures

    Dependency testFixtures(Object notation, Action<? super Dependency> configureAction)
    Declares a dependency on the test fixtures of a component and allows configuring the resulting dependency.
    Parameters:
      `notation` - the coordinates of the component to use test fixtures for
    Since:
      5.6

  - ### variantOf

    Provider<MinimalExternalModuleDependency> variantOf(Provider<MinimalExternalModuleDependency> dependencyProvider, Action<? super ExternalModuleDependencyVariantSpec> variantSpec)
    Allows fine-tuning what variant to select for the target dependency. This can be used to specify a classifier, for example.
    Parameters:
      `dependencyProvider` - the dependency provider
      `variantSpec` - the variant specification
    Returns:
      a new dependency provider targeting the configured variant
    Since:
      6.8

  - ### variantOf

    default Provider<MinimalExternalModuleDependency> variantOf(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible, Action<? super ExternalModuleDependencyVariantSpec> variantSpec)
    Allows fine-tuning what variant to select for the target dependency. This can be used to specify a classifier, for example.
    Parameters:
      `dependencyProviderConvertible` - the dependency provider convertible that returns the dependency provider
      `variantSpec` - the variant specification
    Returns:
      a new dependency provider targeting the configured variant
    Since:
      7.3

  - ### platform

    default Provider<MinimalExternalModuleDependency> platform(Provider<MinimalExternalModuleDependency> dependencyProvider)
    Configures this dependency provider to select the platform variant of the target component
    Parameters:
      `dependencyProvider` - the dependency provider
    Returns:
      a new dependency provider targeting the platform variant of the component
    Since:
      6.8

  - ### platform

    default Provider<MinimalExternalModuleDependency> platform(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible)
    Configures this dependency provider to select the platform variant of the target component
    Parameters:
      `dependencyProviderConvertible` - the dependency provider convertible that returns the dependency provider
    Returns:
      a new dependency provider targeting the platform variant of the component
    Since:
      7.3

  - ### enforcedPlatform

    Provider<MinimalExternalModuleDependency> enforcedPlatform(Provider<MinimalExternalModuleDependency> dependencyProvider)
    Configures this dependency provider to select the enforced-platform variant of the target component
    Parameters:
      `dependencyProvider` - the dependency provider
    Returns:
      a new dependency provider targeting the enforced-platform variant of the component
    Since:
      7.3

  - ### enforcedPlatform

    default Provider<MinimalExternalModuleDependency> enforcedPlatform(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible)
    Configures this dependency provider to select the enforced-platform variant of the target component
    Parameters:
      `dependencyProviderConvertible` - the dependency provider convertible that returns the dependency provider
    Returns:
      a new dependency provider targeting the enforced-platform variant of the component
    Since:
      7.3

  - ### testFixtures

    default Provider<MinimalExternalModuleDependency> testFixtures(Provider<MinimalExternalModuleDependency> dependencyProvider)
    Configures this dependency provider to select the test fixtures of the target component
    Parameters:
      `dependencyProvider` - the dependency provider
    Returns:
      a new dependency provider targeting the test fixtures of the component
    Since:
      6.8

  - ### testFixtures

    default Provider<MinimalExternalModuleDependency> testFixtures(ProviderConvertible<MinimalExternalModuleDependency> dependencyProviderConvertible)
    Configures this dependency provider to select the test fixtures of the target component
    Parameters:
      `dependencyProviderConvertible` - the dependency provider convertible that returns the dependency provider
    Returns:
      a new dependency provider targeting the test fixtures of the component
    Since:
      7.3