akka HttpResponse read body as String scala - scala

Question

So I have a function with this signature (akka.http.model.HttpResponse):
def apply(query: Seq[(String, String)], accept: String): HttpResponse
I simply get a value in a test like:
val resp = TagAPI(Seq.empty[(String, String)], api.acceptHeader)
I want to check its body in a test something like:
resp.entity.asString == "tags"
My question is how I can get the response body as string?

Answer 1

import akka.http.scaladsl.unmarshalling.Unmarshal
implicit val system = ActorSystem("System")
implicit val materializer = ActorFlowMaterializer()
val responseAsString: Future[String] = Unmarshal(entity).to[String]

Answer 2

Since Akka Http is streams based, the entity is streaming as well. If you really need the entire string at once, you can convert the incoming request into a Strict one:
This is done by using the toStrict(timeout: FiniteDuration)(mat: Materializer) API to collect the request into a strict entity within a given time limit (this is important since you don't want to "try to collect the entity forever" in case the incoming request does actually never end):
import akka.stream.ActorFlowMaterializer
import akka.actor.ActorSystem
implicit val system = ActorSystem("Sys") // your actor system, only 1 per app
implicit val materializer = ActorFlowMaterializer() // you must provide a materializer
import system.dispatcher
import scala.concurrent.duration._
val timeout = 300.millis
val bs: Future[ByteString] = entity.toStrict(timeout).map { _.data }
val s: Future[String] = bs.map(_.utf8String) // if you indeed need a `String`

Answer 3

You can also try this one also.
responseObject.entity.dataBytes.runFold(ByteString(""))(_ ++ _).map(_.utf8String) map println

Answer 4

Unmarshaller.stringUnmarshaller(someHttpEntity)
works like a charm, implicit materializer needed as well

Answer 5

Here is simple directive that extracts string from request's body
def withString(): Directive1[String] = {
extractStrictEntity(3.seconds).flatMap { entity =>
provide(entity.data.utf8String)
}
}

Answer 6

Unfortunately in my case, Unmarshal to String didn't work properly complaining on: Unsupported Content-Type, supported: application/json. That would be more elegant solution, but I had to use another way. In my test I used Future extracted from entity of the response and Await (from scala.concurrent) to get the result from the Future:
Put("/post/item", requestEntity) ~> route ~> check {
val responseContent: Future[Option[String]] =
response.entity.dataBytes.map(_.utf8String).runWith(Sink.lastOption)
val content: Option[String] = Await.result(responseContent, 10.seconds)
content.get should be(errorMessage)
response.status should be(StatusCodes.InternalServerError)
}
If you need to go through all lines in a response, you can use runForeach of Source:
response.entity.dataBytes.map(_.utf8String).runForeach(data => println(data))

Answer 7

Here is my working example,
import akka.actor.ActorSystem
import akka.http.scaladsl.Http
import akka.http.scaladsl.model._
import akka.stream.ActorMaterializer
import akka.util.ByteString
import scala.concurrent.Future
import scala.util.{ Failure, Success }
def getDataAkkaHTTP:Unit = {
implicit val system = ActorSystem()
implicit val materializer = ActorMaterializer()
// needed for the future flatMap/onComplete in the end
implicit val executionContext = system.dispatcher
val url = "http://localhost:8080/"
val responseFuture: Future[HttpResponse] = Http().singleRequest(HttpRequest(uri = url))
responseFuture.onComplete {
case Success(res) => {
val HttpResponse(statusCodes, headers, entity, _) = res
println(entity)
entity.dataBytes.runFold(ByteString(""))(_ ++ _).foreach (body => println(body.utf8String))
system.terminate()
}
case Failure(_) => sys.error("something wrong")
}
}