Gradle - Add single file to JAR

If you would like to add multiple files, you can do:

jar{
    from{
        ["aaa.txt","bbb.txt"]
    }
}

To add a single file, you can simply do:

jar {
    from "license.txt"
}

Your solution should also work if you scoped your include to your from by enclosing it in curly braces.