Slug.scala

package util

object Slug {
  def apply(input:String) = slugify(input)

  def slugify(input: String): String = {
    import java.text.Normalizer
    Normalizer.normalize(input, Normalizer.Form.NFD)
      .replaceAll("[^\\w\\s-]", "") // Remove all non-word, non-space or non-dash characters
      .replace('-', ' ')            // Replace dashes with spaces
      .trim                         // Trim leading/trailing whitespace (including what used to be leading/trailing dashes)
      .replaceAll("\\s+", "-")      // Replace whitespace (including newlines and repetitions) with single dashes
      .toLowerCase                  // Lowercase the final results
  }
}

// Example Usage:
Slug("This is the Title of my Blog Post!")
// String = "this-is-the-title-of-my-blog-post

// More "Magic" (though in Scala, it's not really, and for *simple* wrappers, pretty easy to see through):
implicit class StringToSlug(s:String) {
  def slug = Slug(s)
}

// Now you can:
"This is the Title of my Blog Post!".slug
// String = "this-is-the-title-of-my-blog-post

Still after 7 years, it rocks.
I re adapted into Kotlin
https://gist.github.com/raychenon/8fac7e5fb41364694f00e6ce8b8c32a8