5

我正在使用 Spray 来构建 REST API。我的 JSON 数据类型之一是递归的：

case class Container(id: String,
                 name: String,
                 read_only: Boolean,
                 containers: List[Container],
                 content: List[Content])

object PeriusJsonProtocol extends DefaultJsonProtocol {
  implicit val contentFormat = jsonFormat8(Content)
  implicit val containerFormat: JsonFormat[Container] = lazyFormat(jsonFormat5(Container))
}

在 HttpService 中完成路由时，出现以下错误：

Error:(49, 18) could not find implicit value for parameter um: spray.httpx.unmarshalling.FromRequestUnmarshaller[Container]
        entity(as[Container]) { container =>
                 ^

Error:(49, 18) not enough arguments for method as: (implicit um: spray.httpx.unmarshalling.FromRequestUnmarshaller[Container])spray.httpx.unmarshalling.FromRequestUnmarshaller[Container].
Unspecified value parameter um.
        entity(as[Container]) { container =>
                 ^

HttpService 如下所示：

import akka.actor.Actor
import spray.routing._
import spray.httpx.SprayJsonSupport._

import PeriusJsonProtocol._

class RestServiceActor extends Actor with RestService {
  def actorRefFactory = context
  def receive = runRoute(projectsRoute)
}

// this trait defines our service behavior independently from the service actor
trait RestService extends HttpService {
  private val PROJECTS  = "projects"

  val projectsRoute =
    path(PROJECTS) {
      get {
        complete(MongoUtil.getAll(PROJECTS, META) map ContainerMap.fromBson)
        //complete(Container("test", "name", false, List(), List()))
      } ~ post {
        entity(as[Container]) { 
          //complete(MongoUtil.insertProject(container))
          complete(container)
        }
      }
    }
}

尽管该函数返回一个容器列表，但仍在工作中complete。GET但是，注释掉的行get不起作用，并且无法将 Container 隐式转换为post，如错误消息中所示。我应该怎么做才能使容器隐式工作并仍然保持其递归结构？

4

1 回答 1

6

Container 类是根级别的 json，因此您需要将相应的隐式更改为：

implicit val containerFormat: RootJsonFormat[Container] = rootFormat(lazyFormat(jsonFormat5(Container)))
于 2015-10-14T15:52:03.747 回答