Gluon build as single Jar

I'd like to build my Gluon Project as a SINGLE executable jar file.

Currently there is a startup script included with a bin folder and so on.

Is it possible to build a single jar? Or can I include an own gradle task that accomplishes this?

Since I had to build the jar with javapackager I used this plugin: javafx-gradle-plugin

I am relatively new to Gradle so adding the dependencies is just a temporary solution but it works

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'org.javafxports:jfxmobile-plugin:1.0.8'
        classpath group: 'de.dynamicfiles.projects.gradle.plugins', name: 'javafx-gradle-plugin', version: '8.4.1'
    }
}

jfx {
    verbose = true
    mainClass = "package.path.to.main.class.MainClass"
    jfxAppOutputDir = "build/jfx/app" //configurable
    jfxMainAppJarName = "ProjectName.jar"
    deployDir = "src/main/deploy" //for signing

    //many more options, go to link to learn about them
}


jfxJar.doFirst {
    //TODO add all desktop dependencies
    println("adding desktop dependency")
    project.dependencies.add("runtime", "com.gluonhq:charm-desktop:2.1.0")
}