Maven Flatten Plugin – Plugin Documentation

Plugin Documentation

Goals available for this plugin:

Goal Description

flatten:clean This MOJO realizes the goal flatten:clean that deletes any files created by flatten:flatten (more specific the flattened POM file which is by default .flattened-pom.xml). See also MOJO-2030 for further details.

flatten:flatten

This MOJO realizes the goal flatten that generates the flattened POM and #isUpdatePomFile() potentially updates the POM file so that the current org.apache.maven.project.MavenProject's file points to the flattened POM instead of the original pom.xml file. The flattened POM is a reduced version of the original POM with the focus to contain only the important information for consuming it. Therefore information that is only required for maintenance by developers and to build the project artifact(s) are stripped. Starting from here we specify how the flattened POM is created from the original POM and its project:


Element	Transformation	Note
`modelVersion`	Fixed to "4.0.0"	New maven versions will once be able to evolve the model version without incompatibility to older versions if flattened POMs get deployed.
`groupId` `artifactId` `version` `packaging`	resolved	copied to the flattened POM but with inheritance from `parent` as well as with all variables and defaults resolved. These elements are technically required for consumption.
`licenses`	resolved	copied to the flattened POM but with inheritance from `parent` as well as with all variables and defaults resolved. The licenses would not be required in flattened POM. However, they make sense for publication and deployment and are important for consumers of your artifact.
`Model#getDependencies() dependencies`	resolved specially	flattened POM contains the actual dependencies of the project. Test dependencies are removed. Variables and `Model#getDependencyManagement() dependencyManagement` is resolved to get fixed dependency attributes (especially `version`). If `#isEmbedBuildProfileDependencies() embedBuildProfileDependencies` is set to `true`, then also build-time driven `org.apache.maven.model.Profile`s will be evaluated and may add `dependencies`. For further details see `org.apache.maven.model.Profile`s below.
`profiles`	resolved specially	only the `org.apache.maven.model.Activation` and the `dependencies` of a `org.apache.maven.model.Profile` are copied to the flattened POM. If you set the parameter `embedBuildProfileDependencies` to `true` then only profiles `activated` by `JDK` or `OS` will be added to the flattened POM while the other profiles are triggered by the current build setup and if activated their impact on dependencies is embedded into the resulting flattened POM.
`name` `description` `url` `inceptionYear` `organization` `scm` `developers` `contributors` `mailingLists` `Model#getPluginRepositories() pluginRepositories` `issueManagement` `ciManagement` `Model#getDistributionManagement() distributionManagement`	configurable	Will be stripped from the flattened POM by default. You can configure all of the listed elements inside `pomElements` that should be kept in the flattened POM (e.g. <pomElements><name/><description/><developers/><contributors/></pomElements>). For common use-cases there are predefined modes available via the parameter `flattenMode` that should be used in preference.
`prerequisites`	configurable	Like above but by default NOT removed if packaging is "maven-plugin".
`Model#getRepositories() repositories`	configurable	Like two above but by default NOT removed. If you want have it removed, you need to use the parameter `pomElements` and configure the child element `repositories` with value `flatten`.
`parent` `build` `Model#getDependencyManagement() dependencyManagement` `Model#getProperties() properties` `Model#getModules() modules` `Model#getReporting() reporting`	configurable	These elements should typically be completely stripped from the flattened POM. However for ultimate flexibility (e.g. if you only want to resolve variables in a POM with packaging pom) you can also configure to keep these elements. We strictly recommend to use this feature with extreme care and only if packaging is pom (for "Bill of Materials"). In the latter case you configure the parameter `flattenMode` to the value `bom`. If the `build` element contains plugins in the `build/plugins` section which are configured to load extensions, a reduced `build` element containing these plugins will be kept in the flattened pom.

flatten:help Display help information on flatten-maven-plugin.
Call mvn flatten:help -Ddetail=true -Dgoal=<goal-name> to display parameter details.

System Requirements

The following specifies the minimum requirements to run this Maven plugin:

Maven	3.2.5
JDK	1.8

Usage

You should specify the version in your project's plugin configuration:

<project>
  ...
  <build>
    <!-- To define the plugin version in your parent POM -->
    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.codehaus.mojo</groupId>
          <artifactId>flatten-maven-plugin</artifactId>
          <version>1.4.1</version>
        </plugin>
        ...
      </plugins>
    </pluginManagement>
    <!-- To use the plugin goals in your POM or parent POM -->
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>flatten-maven-plugin</artifactId>
      </plugin>
      ...
    </plugins>
  </build>
  ...
</project>

For more information, see "Guide to Configuring Plug-ins"