could not find implicit value for parameter marshaller: spray.httpx.marshalling.ToResponseMarshaller
scala, spray, spray-json
Solution
You need to make sure that the implicit `JsonFormat` for the `Cluster` type is in scope, so that `SprayJsonSupport` knows how to marshall that type. With that you should automatically get support for marshaling `List[Cluster]` from the default formats.
In the posted code `val impCluster = jsonFormat2(Cluster)` defines the `JsonFormat`, but it is not marked as `implicit`, so the typeclass cannot be implicitly resolved. Changing it to
implicit val impCluster = jsonFormat2(Cluster)
should fix the issue.
Problem
I'm using ``` val akkaV = "2.2.3" val sprayV = "1.2.0" Seq( "io.spray" % "spray-can" % sprayV, "io.spray" % "spray-routing" % sprayV, "io.spray" %% "spray-json" % "1.2.5", "io.spray" % "spray-testkit" % sprayV, "com.typesafe.akka" %% "akka-actor" % akkaV, "com.typesafe.akka" %% "akka-testkit" % akkaV, ``` And getting this error: could not find implicit value for parameter marshaller: spray.httpx.marshalling.ToResponseMarshaller[List[org.bwi.models.Cluster]] with this code: ``` object JsonImplicits extends DefaultJsonProtocol { val impCluster = jsonFormat2(Cluster) } trait ToolsService extends HttpService with spray.httpx.SprayJsonSupport { val myRoute = { import JsonImplicits._ path("") { get { getFromResource("tools.html") } } ~ pathPrefix("css") { get { getFromResourceDirectory("css") } } ~ pathPrefix("fonts") { get { getFromResourceDirectory("fonts") } } ~ pathPrefix("js") { get { getFromResourceDirectory("js") } } ~ path("clusters") { get { complete { val result: List[Cluster] = List(Cluster("1", "1 d"), Cluster("2", "2 d"), Cluster("3", "3 d")) result //***** ERROR OCCURS HERE ***** } } } } ``` } I've tried the suggestion on this question but it did not work, same error. I can't seem to figure out what the implicit I need to import is. Any help would be appreciated.