Question

我正在使用play2.5 + play2-reactivemongo 0.12.3。

BSONObjectID作为数组插入，BSONDateTime作为NumberLong插入mongoDB，代码如下。

> db.Example.find()
{ "_id" : { "array" : [ 89, 55, -10, 60, -40, 0, 0, -61, 0, -94, 126, 23 ] }, "created" : NumberLong("1496839744818") }

我想将BSONObjectID作为ObjectID和DateTime插入，作为BSONDateTime插入。是否可以使用类型参数？

TemporalModel.scala

trait TemporalModel {
  var _id: Option[BSONObjectID]
  var created: Option[DateTime]
}

Example.scala

import org.joda.time.DateTime
...

case class Example(
  var_id: Option[BSONObjectID],
  str: String,
  var created: Option[DateTime]
) extends TemporalModel

object Example {

  //implicit val objectIdRead: Reads[BSONObjectID] =
  val objectIdRead: Reads[BSONObjectID] =
    (__ \ "$oid").read[String].map { oid =>
      BSONObjectID(oid)
  }

  //implicit val objectIdWrite: Writes[BSONObjectID] = new Writes[BSONObjectID] {
  val objectIdWrite: Writes[BSONObjectID] = new Writes[BSONObjectID] {
    def writes(objectId: BSONObjectID): JsValue = Json.obj(
      "$oid" -> objectId.stringify
    )
  }

  //implicit val dateTimeRead: Reads[DateTime] =
  val dateTimeRead: Reads[DateTime] =
    (__ \ "$date").read[Long].map { dateTime =>
      new DateTime(dateTime)
  }

  //implicit val dateTimeWrite: Writes[DateTime] = new Writes[DateTime] {
  val dateTimeWrite: Writes[DateTime] = new Writes[DateTime] {
    def writes(dateTime: DateTime): JsValue = Json.obj(
      "$date" -> dateTime.getMillis
    )
  }

  implicit val objectIdFormats = Format(objectIdRead, objectIdWrite)
  implicit val dateTimeFormats = Format(dateTimeRead, dateTimeWrite)
  //implicit val bsonObjectIDJsonFormat = Json.format[BSONObjectID]
  implicit val exampleJsonFormat = Json.format[Example]

  def apply(str: String): Example = {
    new Example(null, str, null)
  }
}

BaseDAO.scala

class BaseDAO[T] {
  ...
  val collectionName: String
  lazy val collection: Future[JSONCollection] = reactiveMongoApi.database.map(_.collection(collectionName))

  def toJs[K : Writes](o: K) = Json.toJson(o).as[JsObject]

  def insert(document: T)(implicit writer: Writes[T]): Future[T] = {
    document._id = Some(BSONObjectID.generate)
    document.created = Some(DateTime.now)
    collection.flatMap(_.insert(toJs(document)))
  }
}

ExampleDAO.scala

trait ExampleDAO extends BaseDAO[Example]

class ExampleDAOImpl @Inject() (val reactiveMongoApi: ReactiveMongoApi) 
extends ExampleDAO {
  val collectionName = "example"
}

Answer 1

问题是你在范围内有太多暗示。但是，由于这些在宏中已得到解决，因此似乎没有编译错误。

你应该做什么：

删除implicit前面的所有Reads修饰符和Writes和BSONObjectID

DateTime

删除bsonObjectIDJsonFormat（其类型与objectIdFormats相同，因此编译器不应允许这样做）

Reactivemongo - BSONObjectID和BSONDateTime插入

1 个答案: