Using a Map to hold routes with Akka

HttpHandler.scala

import scala.collection.mutable.Map
import scala.concurrent.ExecutionContextExecutor

import akka.http.scaladsl.model.ContentTypes
import akka.http.scaladsl.model.HttpEntity
import akka.http.scaladsl.model.HttpEntity.ChunkStreamPart
import akka.http.scaladsl.model.HttpEntity.apply
import akka.http.scaladsl.model.HttpProtocols
import akka.http.scaladsl.model.HttpResponse
import akka.http.scaladsl.model.StatusCode
import akka.http.scaladsl.model.Uri
import akka.stream.scaladsl.Flow
import akka.stream.scaladsl.Source

case class HttpHandler(implicit ec: ExecutionContextExecutor) {
  val notImplemented = HttpResponse(StatusCode.int2StatusCode(404), entity = "Endpoint not implemented, try again with '/query'")
  val routes = Map[Uri.Path, (HttpMethods.Method)]()
  
  def addRoute(path: Uri.Path, method: HttpMethods.Method): Boolean = {
    val _path = routes.get(path)
    _path match {
      case Some(p) => 
          if (p.equals(method)) {
            false
          } else {
            routes.put(path, (method))
            true
          }
      case None => 
          routes.put(path, (method))
          true
    }
  }
  
  def generateResponse(rs: Source[HttpEntity.ChunkStreamPart, Unit], status: Int, errorEntity: String = ""): HttpResponse = {
    errorEntity match {
      case "" =>  
        HttpResponse(StatusCode.int2StatusCode(status), entity = HttpEntity.Chunked(ContentTypes.`application/octet-stream`, rs) ,protocol = HttpProtocols.`HTTP/1.1`)
      case _ =>
        HttpResponse(StatusCode.int2StatusCode(status), entity = HttpEntity.apply(errorEntity) ,protocol = HttpProtocols.`HTTP/1.1`)
    }
  }
  
  def generateResponseWithError(status: Int, errorEntity: String): HttpResponse = {
    generateResponse(Source.empty, status, errorEntity)
  }
}

HttpRoutes.scala

import scala.concurrent.ExecutionContext

import akka.http.scaladsl.model.Uri

case object HttpRoutes {
   implicit val ec = ExecutionContext.Implicits.global
   
   val handler = HttpHandler()
   handler.addRoute(Uri.Path("/query"), HttpMethods.POST)
}

Main.scala

import akka.actor.ActorSystem
import akka.stream.ActorMaterializer

object Main extends App {
   implicit lazy val system = ActorSystem("service")
   implicit val materializer = ActorMaterializer()
   val handler = HttpRoutes.handler
   
   HttpServer.bindServer(9995)(system, materializer, handler)
}