Could not find implicit format for parameter

Question

I have the following case class:

case class Customer(name: String)

That is encoded like this:

class ServiceJsonProtocol extends DefaultJsonProtocol {
  implicit val customerProtocol = jsonFormat1(Customer)
}

The problem is that for this code:

val route =
  path("customer") {
    post {
      entity(as[Customer]) {
        customer => complete {
          customers.add(customer)
          s"got customer with name ${customer.name}"
        }
      }
    }

I am getting this:

 could not find implicit value for parameter um: akka.http.scaladsl.unmarshalling.FromRequestUnmarshaller[Customer]
[error]           entity(as[Customer]) {

What is the issue?

If you're using spray-json, please mention it in your question. Also, take a look at stackoverflow.com/questions/33574176/… — The_Tourist

Emiliano Martinez Emiliano Martinez · Accepted Answer · 2016-12-04T21:25:52

You have to extend SprayJsonSupport. This compiles:

import spray.json._
import akka.http.scaladsl.marshallers.sprayjson.SprayJsonSupport

case class Customer(name: String)

object ServiceJsonProtocol extends DefaultJsonProtocol {
  implicit val customerProtocol = jsonFormat1(Customer)
}

class RateRoutes extends SprayJsonSupport {

  import ServiceJsonProtocol._

  val route =
    path("customer") {
      post {
        entity(as[Customer]) {
          customer => complete {
            customers.add(customer)
            s"got customer with name ${customer.name}"
          }
        }
      }
    }
  }

I suppose your using akka http. With Spray this error should not happen.

Could not find implicit format for parameter

1 Answers