For my bachelor thesis project, I gave Gradle a try. Gradle is a build automation tool like Ant or Maven, well actually more like Maven if you ask me. It has Maven’s convention over configuration approach and combines it with Ant’s flexibility. So far I’m very happy with the configuration options, but of course it’s not used everywhere. Sometimes, libraries that are developed with Gradle as their build tool, need to be used by other (dependency management) tools, e.g., Maven or Ivy. This is the case for my bachelor thesis project.

Luckily, a handy Maven plug-in exists which does exactly this - installing artefacts to the local Maven repository (actually it’s capable of way more, check out the documentation). To use it, make sure that you are applying the Maven plug-in and define a group and version. Both are identical to Maven’s concepts of coordinates. The following listing shows a minimal build.gradle file.

allprojects {
  apply plugin: 'maven'
  group = 'com.example'
  version = '0.1-SNAPSHOT'
}

What’s missing here is the artefact id. The artefact id is actually the root directory’s name. For instance, a project located in /home/user/MyFancyProject will have the artefact id MyFancyProject. Subcomponent artefact ids follow the same rules, i.e., the directory name will always be used. This is also true for sub-subcomponents, e.g., /home/user/MyFancyProject/BusinessLogicComponent/EntitiesComponent will result in artefact ids MyFancyProject, BusinessLogicComponent and EntitiesComponent.

At last, to actually trigger the local installation, execute the install target.

gradle install

To change the output of the Maven plug-in, you can make use of the configure directive. It’s using Groovy’s XML MarkupBuilder, so check out its documentation for more information. Here is a small example which shows the addition of licensing information, packaging and inception year.

allprojects {
  apply plugin: 'maven'
  group = 'com.example'
  version = '0.1-SNAPSHOT'

  configure(install.repositories.mavenInstaller) {
    pom.project {
      inceptionYear '2012'
      packaging 'jar'
      licenses {
        license {
          name 'The Apache Software License, Version 2.0'
          url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
          distribution 'repo'
        }
      }
    }
  }
}