在Scala Play应用程序中没有实现OWrites和Reads

trait Player extends Temp {

  val gameId: BSONObjectID

  val personalDetails: abc.PersonalDetails // <- comes from shared library

}

case class FootballPlayer(var _id: Option[BSONObjectID] = None,gameId: BSONObjectID,personalDetails: abc.PersonalDetails,var created: Option[DateTime] = None,var updated: Option[DateTime] = None
                        ) extends Player

case class VideogamePlayer(var _id: Option[BSONObjectID] = None,var updated: Option[DateTime] = None
                        ) extends Player

所有这些模型,都作为一个伴侣对象play.api.libs.json.Reads和play.api.libs.json.OWrites定义.

例如：

object FootballPlayer {

  import play.api.libs.functional.syntax._
  import play.api.libs.json.Reads._
  import play.api.libs.json._
  import reactivemongo.play.json.BSONFormats.BSONObjectIDFormat

  implicit val footballPlayerReads: Reads[FootballPlayer] = (
    (__  "_id").readNullable[BSONObjectID].map(_.getOrElse(BSONObjectID.generate)).map(Some(_)) and
      (__  "gameId").read[BSONObjectID] and
      (__  "personalDetails").read[abc.PersonalDetails] and
      (__  "created").readNullable[DateTime].map(_.getOrElse(new DateTime())).map(Some(_)) and
      (__  "updated").readNullable[DateTime].map(_.getOrElse(new DateTime())).map(Some(_))
    ) (FootballPlayer.apply _)


  implicit val sharedPersonalDetailsWrites: Writes[abc.PersonalDetails] = abc.PersonalDetails.sharedPersonalDetailsWrites

  implicit val footballPlayerWrites: OWrites[FootballPlayer] = (
    (__  "_id").writeNullable[BSONObjectID] and
      (__  "gameId").write[BSONObjectID] and
      (__  "personalDetails").write[abc.PersonalDetails] and
      (__  "created").writeNullable[DateTime] and
      (__  "updated").writeNullable[DateTime]
    ) (unlift(FootballPlayer.unapply))

}

现在我想将它们存储在不同的集合中,但是我只想要一个DAO,所以我实现了以下几点：

trait PlayerDAO[T <: Player] {

  def findById(_id: BSONObjectID)(implicit reads: Reads[T]): Future[Option[T]]

  def insert(t: T)(implicit writes: OWrites[T]): Future[T]

}

class MongoPlayerDAO[T <: Player] @Inject()(
                                           playerRepository: PlayerRepository[T]
                                         ) extends PlayerDAO[T] {

  def findById(_id: BSONObjectID)(implicit reads: Reads[T]): Future[Option[T]] = playerRepository.findById(_id)

  def insert(t: T)(implicit writes: OWrites[T]): Future[T] = playerRepository.insert(t).map(_ => t)

}

然后,我有以下存储库：

class PlayerService[T <: Player] @Inject()(playerDAO: PlayerDAO[T])(implicit reads: Reads[T],writes: OWrites[T]) {

  def findById(_id: BSONObjectID): Future[Option[T]] = playerDAO.findById(_id)


  def save(t: T): Future[T] = playerDAO.save(t)

}

我的模块如下所示：

class PlayerModule extends AbstractModule with ScalaModule {

  def configure() {
    bind[PlayerDAO[FootballPlayer]].to[MongoPlayerDAO[FootballPlayer]]
    bind[PlayerDAO[VideogamePlayer]].to[MongoPlayerDAO[VideogamePlayer]]
    // ...
    ()
  }
}

在我的Play控制器中,我注入以下内容：

import models.FootballPlayer._
import models.VideogamePlayer._ 

class PlayerController @Inject()(
                                 val messagesApi: MessagesApi,footballPlayerService: PlayerService[FootballPlayer],videogamePlayerService: PlayerService[VideogamePlayer]
                               ) extends Controller with I18nSupport

不幸的是,我得到以下异常：

1) No implementation for
play.api.libs.json.OWrites was bound. 2) No
implementation for play.api.libs.json.OWrites
was bound. 3) No implementation for
play.api.libs.json.Reads was bound. 4) No
implementation for play.api.libs.json.Reads
was bound.

如何解决这个问题？