build.gradle

apply plugin: 'java'
apply plugin: 'maven-publish'
apply plugin: 'idea'
apply plugin: 'eclipse'

String buildNum = System.getenv("TRAVIS_BUILD_NUMBER")
if (buildNum != null) version += "+" + buildNum

repositories {
    mavenLocal()
    mavenCentral()
}

dependencies {
}

jar {
    manifest {
        if (project.hasProperty("mainClass")) attributes 'Main-Class': mainClass
    }
}

task testJar(type: Jar, dependsOn: javadoc) {
    from sourceSets.main.output
    from sourceSets.test.output

    manifest {
        if (project.hasProperty("testMainClass")) attributes "Main-Class": testMainClass
    }
    classifier = 'test'
}

task sourceJar(type: Jar) {
    from sourceSets.main.allSource
    classifier = 'sources'
}

task javadocJar(type: Jar, dependsOn: javadoc) {
    from 'build/docs/javadoc'
    classifier = 'javadoc'
}

build {
    dependsOn testJar
    dependsOn sourceJar
    dependsOn javadocJar
}

publishing {
    publications {
        maven(MavenPublication) {
            from components.java
            artifact testJar
            artifact sourceJar
            artifact javadocJar
        }
    }

    repositories.maven {
        if (!project.hasProperty("mavenUrl")) return;

        credentials {
            username System.getenv("CI_DEPLOY_USERNAME")
            password System.getenv("CI_DEPLOY_PASSWORD")
        }
        url mavenUrl
    }
}