TopolearnSharing a library with other teams or the world means producing a correct Maven publication.
The maven-publish plugin publishes a project's artifacts to any Maven-compatible repository: Maven Central (via Sonatype), a company Nexus/Artifactory, GitHub Packages, or mavenLocal() (~/.m2) for local testing.
Configure a publication from the java component and one or more repositories:
publishing {
publications { create<MavenPublication>("maven") { from(components["java"]) } }
repositories { maven { url = uri("https://nexus.acme.com/repository/maven-releases") ; credentials { ... } } }
}This generates tasks like publishMavenPublicationToMavenRepository and the aggregate publish, plus publishToMavenLocal.
The component maps Gradle's api dependencies to Maven compile scope and implementation to runtime, so consumers using Maven get a sensible POM. Gradle also publishes a .module file with richer metadata (variants, capabilities) that Gradle consumers use.
Add java { withSourcesJar(); withJavadocJar() } to publish source and Javadoc jars, which Maven Central requires, together with POM metadata (name, description, URL, license, developers, SCM) set through pom { }. The signing plugin signs artifacts with GPG; Central also requires it.
Use group and version for the coordinates; -SNAPSHOT versions go to snapshot repositories and can be republished. Never put credentials in the script: read them from gradle.properties in the home directory or environment variables (providers.environmentVariable("NEXUS_TOKEN")).
Example
plugins { `java-library`; `maven-publish`; signing }
group = "com.acme"
version = "1.2.0"
java { withSourcesJar(); withJavadocJar() }
publishing {
publications {
create<MavenPublication>("maven") {
from(components["java"])
pom {
name = "acme-core"
description = "Core utilities for ACME services"
url = "https://github.com/acme/core"
licenses { license { name = "Apache-2.0" } }
developers { developer { id = "ada"; name = "Ada L." } }
scm { url = "https://github.com/acme/core" }
}
}
}
repositories {
maven {
name = "nexus"
url = uri("https://nexus.acme.com/repository/maven-releases")
credentials(PasswordCredentials::class) // nexusUsername / nexusPassword properties
}
}
}
signing { useGpgCmd(); sign(publishing.publications["maven"]) }
// $ ./gradlew publishToMavenLocal $ ./gradlew publishRemember
- maven-publish creates publications from the java component
- api maps to Maven compile scope, implementation to runtime
- withSourcesJar/withJavadocJar, POM metadata and signing are needed for Central
- Keep credentials in properties or environment variables