编组和解组MessageEntity

Question

让我们从一段代码开始：

val authData = AuthenticationData("user", "password", None)
val marshalledData: Future[ResponseEntity] = Marshal(authData).to[MessageEntity]
val unmarshalledData: Future[AuthenticationData] = marshalledData.flatMap((data: MessageEntity) =>
      Unmarshal(data).to[AuthenticationData])

编组按预期工作。有转换为json的导入含义：

import akka.http.scaladsl.marshallers.sprayjson.SprayJsonSupport._
import spray.json._
import com.onix.messages.JsonProtocolReadWrite._

由于某种原因，解组不起作用：

MarshallerTest.scala:22: could not find implicit value for parameter um: akka.http.scaladsl.unmarshalling.Unmarshaller[akka.http.scaladsl.model.MessageEntity,com.adform.dco.onix.messages.AuthenticationData]
[error]     Unmarshal(data).to[AuthenticationData]}

RootJsonFormat[AuthenticationData]在JsonProtocolReadWrite下实施，因此可在范围内使用。

修改 JsonProtocolReadWrite

的相关部分

object JsonProtocolReadWrite extends DefaultJsonProtocol {
  implicit object AuthDataFormat extends RootJsonFormat[AuthenticationData] {
    def write(c: AuthenticationData) = {
      val ip: JsValue = c.ipAddress.map(JsString(_)).getOrElse(JsNull)
      JsObject(
        "Username" -> JsString(c.userName),
        "Password" -> JsString(c.password),
        "ClientIp" -> ip
      )
    }


    def read(value: JsValue): AuthenticationData = value.asJsObject.getFields("Username", "Password", "ClientIp") match {
      case Seq(JsString(user), JsString(password), JsString(ip)) => AuthenticationData(user, password, Some(ip))
      case Seq(JsString(user), JsString(password), JsNull) => AuthenticationData(user, password, None)
      case _ => deserializationError("AuthenticationData object expected")
    }
  }
 }