Gradle Plugin

Bnd includes a plugin for Gradle users to build bnd projects. The biz.aQute.bnd.gradle jar contains the bnd Gradle plugin. This plugin requires at least Gradle 2.0.

The bnd Gradle plugin builds a project based upon the information specified in the project's bnd.bnd file and the workspace's cnf/build.bnd file.

The bnd Gradle plugin has the Gradle plugin name biz.aQute.bnd.

Workspace

When creating the cnf project for a new workspace with bndtools, by default, the files for a gradle build will be installed the workspace. This includes the following files in the root of the workspace:

• gradle.properties - Some initial properties to configure the Gradle build for the workspace.
• settings.gradle - Initializes the projects to be included in the Gradle build for the workspace.
• build.gradle - Configures the projects in the Gradle build for the workspace.

These files can be modified to customize the overall Gradle build for the workspace. If special Gradle build behavior is needed, beyond changes to the project's bnd.bnd file, then you should place a build.gradle file in the root of the project and place your customizations in there.

Also, cnf/gradle/biz.aQute.bnd.gradle.jar is installed which is referenced by the gradle.properties file as the location of the bnd Gradle plugin.

Using Bnd Gradle Plugin

If you are using the Gradle build added by bndtools when creating the cnf project in your workspace, you don't need to do anything else. If you want to use the bnd Gradle plugin in your existing Gradle build, you need to add the bnd Gradle plugin jar to your buildscript classpath and then apply the plugin to your project. For example:

buildscript {
  dependencies {
    classpath files('path/to/biz.aQute.bnd.gradle.jar')
  }
}
apply plugin: 'biz.aQute.bnd'

We plan to make the bnd Gradle plugin available for use by the new Gradle plugins DSL soon.

Gradle Tasks

The bnd Gradle plugin extends the standard Gradle Java plugin. It modifies some of the standard Java plugin tasks as necessary and also adds some additional tasks. Running gradle tasks --all in a project will provide a complete list of the tasks available within the project.

The dependencies for the project are configured from the path information specified in the bnd.bnd file such as -buildpath and -testpath. These paths are then used by various tasks such as compileJava and compileTestJava.

The jar task uses bnd to build the project's bundles.

The test task runs any plain JUnit tests in the project.

The check task runs any OSGi JUnit tests in the project by launching a framework and running the tests in the launched framework.

New Tasks

The release task releases the project's bundles to the -releaserepo, if one is configured for the project.

The releaseNeeded task releases the project and all projects it depends on.

The checkNeeded task runs the check task on the project and all projects it depends on.

The cleadNeeded task cleans the project and all projects it depends on.

The export.name tasks, one per bndrun file in the project, exports the name.bndrun file to an executable jar.

The export task will export all the bndrun files to executable jars.

The runbundles.name tasks, one per bndrun file in the project, creates a distribution of the -runbundles of the name.bndrun file.

The runbundles task will create distributions of the runbundles for all the bndrun files.

The echo task will display some help information on the dependencies, paths and configuration of the project.

The bndproperties task will display the bnd properties of the project.

Customizing a project's Gradle build

If you do need to write a build.gradle file for a bnd project, there are some properties of the bnd Gradle plugin you will find useful.

• The bndWorkspace property of the rootProject contains the Workspace object.
• The bnd.project property of the project contains the Project object.

Bnd properties for a project can be accessed in several ways. Given the example property name foo, you can use the bnd function, bnd('foo', 'defaultValue'), or directly from the bnd extension, bnd.foo. To access bnd properties without any macro processing you can use the bndUnprocessed function, bndUnprocessed('foo', 'defaultValue').

For full details on what the bnd Gradle plugin does, check out the source code.