Package: org.gradle.api.artifacts

## [Java] Interface ResolutionStrategy

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

  Examples:

       apply plugin: 'java' //so that there are some configurations

       configurations.all {
         resolutionStrategy {
           // fail eagerly on version conflict (includes transitive dependencies)
           // e.g. multiple different versions of the same dependency (group and name are equal)
           failOnVersionConflict()

           // force certain versions of dependencies (including transitive)
           //  *append new forced modules:
           force 'asm:asm-all:3.3.1', 'commons-io:commons-io:1.4'
           //  *replace existing forced modules with new ones:
           forcedModules = ['asm:asm-all:3.3.1']

           // add dependency substitution rules
           dependencySubstitution {
             substitute module('org.gradle:api') with project(':api')
             substitute project(':util') with module('org.gradle:util:3.0')
           }

           // cache dynamic versions for 10 minutes
           cacheDynamicVersionsFor 10*60, 'seconds'
           // don't cache changing modules at all
           cacheChangingModulesFor 0, 'seconds'
         }
       }

  Since:
    1.0-milestone-6

- - ### Methods Summary

    Methods
    Type | Name and description
    --- | ---
    `void` | `cacheChangingModulesFor(int value, String units)` Sets the length of time that changing modules will be cached, with units expressed as a String.
    `void` | `cacheChangingModulesFor(int value, TimeUnit units)` Sets the length of time that changing modules will be cached.
    `void` | `cacheDynamicVersionsFor(int value, String units)` Sets the length of time that dynamic versions will be cached, with units expressed as a String.
    `void` | `cacheDynamicVersionsFor(int value, TimeUnit units)` Sets the length of time that dynamic versions will be cached.
    `ResolutionStrategy` | `componentSelection(Action<? super ComponentSelectionRules> action)` The componentSelection block provides rules to filter or blacklist certain components from appearing in the resolution result.
    `ResolutionStrategy` | `dependencySubstitution(Action<? super DependencySubstitutions> action)` Configures the set of dependency substitution rules for this configuration.
    `ResolutionStrategy` | `eachDependency(Action<? super DependencyResolveDetails> rule)` Adds a dependency substitution rule that is triggered for every dependency (including transitive) when the configuration is being resolved.
    `ResolutionStrategy` | `failOnVersionConflict()` In case of conflict, Gradle by default uses the newest of conflicting versions.
    `ResolutionStrategy` | `force(Object... moduleVersionSelectorNotations)` Allows forcing certain versions of dependencies, including transitive dependencies.
    `ComponentSelectionRules` | `getComponentSelection()` Returns the currently configured version selection rules object.
    `DependencySubstitutions` | `getDependencySubstitution()` Returns the set of dependency substitution rules that are set for this configuration.
    `Set<ModuleVersionSelector>` | `getForcedModules()` Returns currently configured forced modules.
    `ResolutionStrategy` | `setForcedModules(Object... moduleVersionSelectorNotations)` Allows forcing certain versions of dependencies, including transitive dependencies.

- - ### Method Detail

    - #### public void cacheChangingModulesFor(int value, String units)

      Sets the length of time that changing modules will be cached, with units expressed as a String.

      A convenience method for cacheChangingModulesFor(int, java.util.concurrent.TimeUnit) with units expressed as a String. Units are resolved by calling the `valueOf(String)` method of TimeUnit with the upper-cased string value.

      Parameters:
        `value` - The number of time units
        `units` - The units
      Since:
        1.0-milestone-6

    - #### public void cacheChangingModulesFor(int value, TimeUnit units)

      Sets the length of time that changing modules will be cached.

      Gradle caches the contents and artifacts of changing modules. By default, these cached values are kept for 24 hours, after which the cached entry is expired and the module is resolved again.

      Use this method to provide a custom expiry time after which the cached entries for any changing module will be expired.

      Parameters:
        `value` - The number of time units
        `units` - The units
      Since:
        1.0-milestone-6

    - #### public void cacheDynamicVersionsFor(int value, String units)

      Sets the length of time that dynamic versions will be cached, with units expressed as a String.

      A convenience method for cacheDynamicVersionsFor(int, java.util.concurrent.TimeUnit) with units expressed as a String. Units are resolved by calling the `valueOf(String)` method of TimeUnit with the upper-cased string value.

      Parameters:
        `value` - The number of time units
        `units` - The units
      Since:
        1.0-milestone-6

    - #### public void cacheDynamicVersionsFor(int value, TimeUnit units)

      Sets the length of time that dynamic versions will be cached.

      Gradle keeps a cache of dynamic version => resolved version (ie 2.+ => 2.3). By default, these cached values are kept for 24 hours, after which the cached entry is expired and the dynamic version is resolved again.

      Use this method to provide a custom expiry time after which the cached value for any dynamic version will be expired.

      Parameters:
        `value` - The number of time units
        `units` - The units
      Since:
        1.0-milestone-6

    - #### @Incubating public ResolutionStrategy componentSelection(Action<? super ComponentSelectionRules> action)

      The componentSelection block provides rules to filter or blacklist certain components from appearing in the resolution result.

      Parameters:
        `action` - Action to be applied to the ComponentSelectionRules
      Returns:
        this ResolutionStrategy instance
      Since:
        2.2

    - #### @Incubating public ResolutionStrategy dependencySubstitution(Action<? super DependencySubstitutions> action)

      Configures the set of dependency substitution rules for this configuration. The action receives an instance of DependencySubstitutions which can then be configured with substitution rules.

      Examples:

           // add dependency substitution rules
           configurations.all {
             resolutionStrategy.dependencySubstitution {
               // Substitute project and module dependencies
               substitute module('org.gradle:api') with project(':api')
               substitute project(':util') with module('org.gradle:util:3.0')

               // Substitute one module dependency for another
               substitute module('org.gradle:api:2.0') with module('org.gradle:api:2.1')
             }
           }

      Returns:
        this ResolutionStrategy instance
      See Also:
        DependencySubstitutions
      Since:
        2.5

    - #### @Incubating public ResolutionStrategy eachDependency(Action<? super DependencyResolveDetails> rule)

      Adds a dependency substitution rule that is triggered for every dependency (including transitive) when the configuration is being resolved. The action receives an instance of DependencyResolveDetails that can be used to find out what dependency is being resolved and to influence the resolution process. Example:

           configurations {
             compile.resolutionStrategy {
               eachDependency { DependencyResolveDetails details ->
                 //specifying a fixed version for all libraries with 'org.gradle' group
                 if (details.requested.group == 'org.gradle') {
                   details.useVersion '1.4'
                 }
               }
               eachDependency { details ->
                 //multiple actions can be specified
                 if (details.requested.name == 'groovy-all') {
                    //changing the name:
                    details.useTarget group: details.requested.group, name: 'groovy', version: details.requested.version
                 }
               }
             }
           }

      The rules are evaluated in order they are declared. Rules are evaluated after forced modules are applied (see force(Object...)
      Returns:
        this
      Since:
        1.4

    - #### public ResolutionStrategy failOnVersionConflict()

      In case of conflict, Gradle by default uses the newest of conflicting versions. However, you can change this behavior. Use this method to configure the resolution to fail eagerly on any version conflict, e.g. multiple different versions of the same dependency (group and name are equal) in the same Configuration. The check includes both first level and transitive dependencies. See example below:

           apply plugin: 'java' //so that there are some configurations

           configurations.all {
             resolutionStrategy.failOnVersionConflict()
           }

      Returns:
        this resolution strategy instance
      Since:
        1.0-milestone-6

    - #### public ResolutionStrategy force(Object... moduleVersionSelectorNotations)

      Allows forcing certain versions of dependencies, including transitive dependencies. Appends new forced modules to be considered when resolving dependencies.

      It accepts following notations:

      - String in a format of: 'group:name:version', for example: 'org.gradle:gradle-core:1.0'
      - instance of ModuleVersionSelector
      - any collection or array of above will be automatically flattened
      Example:

           apply plugin: 'java' //so that there are some configurations

           configurations.all {
             resolutionStrategy.force 'asm:asm-all:3.3.1', 'commons-io:commons-io:1.4'
           }

      Parameters:
        `moduleVersionSelectorNotations` - typically group:name:version notations to append
      Returns:
        this ResolutionStrategy instance
      Since:
        1.0-milestone-7

    - #### @Incubating public ComponentSelectionRules getComponentSelection()

      Returns the currently configured version selection rules object.

      Returns:
        the version selection rules
      Since:
        2.2

    - #### @Incubating public DependencySubstitutions getDependencySubstitution()

      Returns the set of dependency substitution rules that are set for this configuration.

      Since:
        2.5

    - #### public Set<ModuleVersionSelector> getForcedModules()

      Returns currently configured forced modules. For more information on forcing versions see force(Object...)

      Returns:
        forced modules
      Since:
        1.0-milestone-7

    - #### public ResolutionStrategy setForcedModules(Object... moduleVersionSelectorNotations)

      Allows forcing certain versions of dependencies, including transitive dependencies. Replaces existing forced modules with the input.

      For information on notations see force(Object...)

      Example:

           apply plugin: 'java' //so that there are some configurations

           configurations.all {
             resolutionStrategy.forcedModules = ['asm:asm-all:3.3.1', 'commons-io:commons-io:1.4']
           }

      Parameters:
        `moduleVersionSelectorNotations` - typically group:name:version notations to set
      Returns:
        this ResolutionStrategy instance
      Since:
        1.0-milestone-7