Uber JAR with Gradle Kotlin DSL

November 20, 2021

What's inside this article ⌄

Gradle Kotlin DSL uber JAR
How to build fat JAR Gradle Kotlin
Gradle Kotlin create uber JAR
Gradle Kotlin shadow JAR
How to make an uber jar Gradle Kotlin DSL
How to make a fat jar Gradle Kotlin DSL

Let’s add this to build.gradle.kts file:

tasks.register<Jar>("uberJar") {
    archiveClassifier.set("uber")
    from(sourceSets.main.get().output)
    dependsOn(configurations.runtimeClasspath)
    from({
        configurations.runtimeClasspath.get().filter { it.name.endsWith("jar") }.map { zipTree(it) }
    })
}

After that, you can build the jar with dependencies:

./gradlew uberJar

Possible errors

No main manifest attribute

Error: no main manifest attribute, in /path/to/your/jar

You need to add a key to your manifest containing the full name of the main class. See this article.

Invalid signature file digest

Error: Invalid signature file digest for Manifest main attributes.

You need to exclude files with extensions .SF, .DSA, .RSA from the assembly.

See this article.