MyRepoServlet.scala

class MyRepoServlet(val system: ActorSystem) extends ScalatraServlet with ScalateSupport with FileUploadSupport with FutureSupport with SlickSupport {

  configureMultipartHandling(MultipartConfig(maxFileSize = Some(3 * 1024 * 1024), fileSizeThreshold = Some(1024 * 1024 * 1024)))

  protected implicit def executor: ExecutionContext = system.dispatcher

  def processFile(upload: FileItem) = {

    val filePath: String = "/tmp/"
    println(">> " + upload.getName)
    try {
      val file: File = new File(filePath + upload.getName)
      upload.write(file)
    } catch {
      case e: IOException ⇒ println("Error " + e)
    }
  }

  get("/uploadMole") {
    contentType = "text/html"
    new AsyncResult() {
      val is = Future {
        ssp("/uploadMole", "body" -> "Please upload an om file below!")
      }
    }
  }

 post("/uploadMole") {
    contentType = "text/html"

    val x = new AsyncResult() {
      val is = Future {
        try {
          val document: FileItem = fileParams("file")
          println("file name: " + document.name)
          processFile(document)
        } catch {
          case e: IOException ⇒ println("IO Error " + e)
          case s: SecurityException ⇒ println("Security Error " + s)
        }
}
}
}

uploadMole.ssp

<form name="data" action="/uploadMole" method="POST" enctype="multipart/form-data">
    <input type="File" name="file"><br>
    <input type="Submit">
</form>