Example: Minimal HTTP server for static content using Scala and Akka - HTTP

application.confg

akka.http.server {
  parsing {
    max-content-length = 110M
  }
}

akka {
  loglevel = DEBUG
}

http {
  ip = "localhost"
  port = 4242
}

build.sbt

name := "nallo"

version := "1.0"

scalaVersion := "2.11.7"

// Akka
libraryDependencies ++= {
  val akkaV       = "2.3.12"
  val akkaStreamV = "1.0"
  val scalaTestV  = "2.2.5"
  Seq(
    "com.typesafe.akka" %% "akka-actor"                           % akkaV,
    "com.typesafe.akka" %% "akka-http-core-experimental"          % akkaStreamV,
    "com.typesafe.akka" %% "akka-http-experimental"               % akkaStreamV,
    "com.typesafe.akka" %% "akka-http-spray-json-experimental"    % akkaStreamV,
  )
}
// assembly name
assemblyJarName in assembly := "nallo.jar"

main.scala

import akka.actor.{ActorSystem}
import akka.event.Logging
import akka.http.scaladsl.Http
import akka.http.scaladsl.model._
import akka.http.scaladsl.server.Directives._
import akka.stream.{ActorMaterializer}
import com.typesafe.config.ConfigFactory
import java.nio.file.{Files, Paths}
import akka.http.scaladsl.model.StatusCodes._

object routes {

  val workingDirectory = System.getProperty("user.dir")

  private def getExtensions(fileName: String) : String = {

    val index = fileName.lastIndexOf('.')
    if(index != 0) {
      fileName.drop(index+1)
    }else
      ""
  }

  private def getDefaultPage = {

    val fullPath = List(Paths.get(workingDirectory + "/index.html"),Paths.get(workingDirectory + "/index.htm"))
    val res = fullPath.filter(x => Files.exists(x))
    if(!res.isEmpty)
      res.head
    else
      Paths.get("")
  }

  def generate = {
    logRequestResult("nallo-micro-http-server") {
      get {
        entity(as[HttpRequest]) { requestData =>
          complete {

            val fullPath = requestData.uri.path.toString match {
              case "/"=> getDefaultPage
              case "" => getDefaultPage
              case _ => Paths.get(workingDirectory +  requestData.uri.path.toString)
            }

            val ext = getExtensions(fullPath.getFileName.toString)
            val c : ContentType = ContentType(MediaTypes.forExtension(ext).getOrElse(MediaTypes.`text/plain`))
            val byteArray = Files.readAllBytes(fullPath)
            HttpResponse(OK, entity = HttpEntity(c, byteArray))
          }
        }
      }
    }
  }
}


object Main extends App {

  implicit val system = ActorSystem()
  implicit val executor = system.dispatcher
  implicit val materializer = ActorMaterializer()

  val config = ConfigFactory.load()
  val logger = Logging(system, getClass)

  Http().bindAndHandle(routes.generate, config.getString("http.ip"), config.getInt("http.port"))
}

plugins.sbt

addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.1")