Akka-Http client: How to get binary data from an http response? - scala

Question

I call an API to get a zip file response. The API responds correctly but I am unable to get the byte array from response because the future that should complete on getting the ByteString never completes:
val authorization = akka.http.javadsl.model.headers.Authorization.basic("xxxxx", "xxxxxx")
val query = Map("fed" -> "xxxx", "trd" -> "yyy", "id" -> "zzz")
val request = HttpRequest(HttpMethods.GET, Uri("https://xxxx.yyyy.com/ggg/ttt.php").withQuery(Query(params = query))).addHeader(authorization)
val responseFut = http.singleRequest(request)
responseFut1.map(response => {
println("*******************************")
println(response)
response.status match {
case akka.http.javadsl.model.StatusCodes.OK => {
println("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^" + response._3)
val entityFut = response.entity.toStrict(60.seconds)
val byteStringFut = entityFut.flatMap(entity => {
entity.dataBytes.runFold(ByteString.empty)(_ ++ _)
})
println("#############################")
try {
byteStringFut.map(x => {
//this never prints =======================================problem
println("----------------------------" + x.toArray[Byte])
})
}catch{
case e: Exception => println("Error: " + e)
}
}
case _ => {}
}
})
If I print out the response this is what it looks like:
*******************************
HttpResponse(200 OK,List(Date: Fri, 08 Sep 2017 20:58:43 GMT, Server: Apache/2.4.18 (Ubuntu), Content-Disposition: attachment; filename="xxxxx.zip", Pragma: public, Cache-Contr
ol: public, must-revalidate, Content-Transfer-Encoding: binary),HttpEntity.Chunked(application/x-zip),HttpProtocol(HTTP/1.1))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^HttpEntity.Chunked(application/x-zip)
#############################
So response is coming back fine, but I still cannot get the binary data for the zip file.
We use akka-http in other places to call APIs that return json response and this approach seems to work fine there.
Why doesnt it work here? What am I doing wrong?
Any advice is appreciated.
Thanks.
Update
Adding byteStringFut.failed.foreach(println(_)) shows this exception: akka.http.scaladsl.model.EntityStreamException: HTTP chunk size exceeds the configured limit of 1048576 bytes

Answer 1

It looks like something went wrong and an exception was thrown in the async computation. You can check the exception by inspecting Future in the following way:
byteStringFut.failed.foreach(println)