Generate aggregate pom with maven-publish

Help/Discuss
1

Hello,

I am new to Gradle and currently trying to create a multi-module skeleton as a base to transform my old maven projects. I am trying to use the maven-publish plugin to generate pom-files to be uploaded to a maven repo and to be used locally for users who might want to build the project with maven instead of gradle.
For example I have the directory api in which I would like to generate an aggregate pom that lists each subdirectory inside this api-directory as a module but don’t know how to achieve that automatically (without adding an entry for each module to the generator configuration).

Here is my current build.gradle:

allprojects {
	group = 'hello'
	version = '0.0.1-SNAPSHOT'
}

subprojects {
    apply plugin: 'java'
	apply plugin: 'maven-publish'

    repositories {
        mavenCentral()
    }

	dependencies {
		compile 'org.slf4j:slf4j-api:1.7.25'
		compile 'org.apache.commons:commons-lang3:3.6'
		compileOnly 'com.google.code.findbugs:jsr305:3.0.1'
		testCompileOnly 'com.google.code.findbugs:jsr305:3.0.1'
		testCompile 'junit:junit:4.12'
	}
	
	publishing {
		publications {
			mavenJava(MavenPublication) { 
				from project.components.java
				pom.withXml {
					asNode().appendNode("name", project.name)
					asNode().appendNode("description", project.description)
				}
			}
			/*
			mavenClassesJar(MavenPublication) {
				from components.java
				artifact(sourcesJar) {
					classifier = 'sources'
				}
				artifact(javadocJar) {
					classifier = 'javadoc'
				}
			}
			*/
		}
	}

	model {
		tasks.generatePomFileForMavenJavaPublication {
			destination = file("pom.xml")
		}
	}
	
}


project(':common:model') {
}

project(':api:remote-api') {
	description = "Description of the remote api..."
	dependencies {
		compileOnly project(':common/model')
	}
	
	
	publishing {
		publications {
			mavenJava(MavenPublication) { 
				pom.withXml {
				}
			}
		}
	}
}

project(':api') {
	dependencies {
		compileOnly project(':api:frontend-api')
		compileOnly project(':api:remote-api')
	}
}
project(':runtime') {
	dependencies {
		compile project(':api')
	}
}

And my settings.gradle:

rootProject.name = 'my-example-architecture'

include 'common:model'
include 'api:frontend-api'
include 'api:remote-api'
include 'api'
include 'runtime'

What I want to achieve should look similar to this one:

/api/pom.xml:
…
<groupId>hello</groupId>
<artifactId>api</artifactId>
<packaging>pom</packaging>
<modules>
<module>remote-api</module>
<module>frontend-api</module>
…
</modules>

So for each module/project in the api-directory there should be an module-entry in the pom.xml but currently this doesn’t get generated. So if a user decides to build the whole stuff with maven it would be neccessary to walk through the directories and run mvn on each pom.xml file manually. Is there any solution/workaround for this or is it so unusual trying to make a setup with an automatic co-existence of gradle and maven?

2

I would say this is pretty unusual to try to have both in the same repo. This doesn’t do exactly what you want, but maybe it’d help? https://bitbucket.org/xenworks/bom/src/master/build.gradle (I was generating my own BOM)

3

Okay thank you for your feedback. Guess I could try to write something to detect aggregator projects, parse their modules and create a special pom for them. But maybe I should really reconsider that plan and just keep it simple and let people only build the code with gradle. Shouldn’t be hard to achieve for developers who really need to build some version on their own and makes the dependency management easier to manage. =)