example of gradle, kotlin, shadow jar and application plugin

build.gradle.kts

import org.jetbrains.kotlin.gradle.tasks.KotlinCompile

plugins {
    application
    kotlin("jvm") version "1.3.50"
    id("com.github.johnrengelman.shadow") version "5.1.0"
}


group = "eu.wojciechzurek"
version = "1.0-SNAPSHOT"
application{
    mainClassName = "eu.wojciechzurek.example.MainKt"
}


repositories {
    mavenCentral()
}

dependencies {
    implementation(kotlin("stdlib-jdk8"))
}

tasks.withType<KotlinCompile> {
    kotlinOptions.jvmTarget = "1.8"
}

tasks.withType<Jar> {
    manifest {
        attributes(
            mapOf(
                "Main-Class" to application.mainClassName
            )
        )
    }
}