播放框架JSON解析错误

我有以下数据类型：

case class DataPoints(fromSource: String, dataPoints: Seq[DataPoint])
object DataPoints {

  implicit val tsFormat = Json.format[DataPoint]

  implicit val tsDataPointsFormat: Format[DataPoints] =
    ((__ \ "fromSource").format[String] ~
      (__ \ "dataPoints").format[Seq[DataPoint]]
      )(DataPoints.apply, unlift(DataPoints.unapply))
}

在我使用此Json转换的地方：

  private def toDataPointSeq(consumerRecords: Seq[ConsumerRecord[String, String]]) = {
    import com.model.DataPoints._
    consumerRecords.map {
      case record =>
        logger.info(s"value obtained is ${record.value()}")
        val jsonIs = Json.toJson(record.value()).validate[DataPoints].asOpt
        logger.info(s"json obtained is $jsonIs") // prints None
        jsonIs
    }.collect {
      case someDataPts if someDataPts.isDefined => someDataPts.get.dataPoints
    }
  }

即使line record.value（）打印以下内容，我得到的json也会返回为None：

{  
   "fromSource":"kafkaProducer",
   "dataPoints":[  
      {  
         "metric":"dataPoint.Active",
         "timestamp":1453830484838,
         "value":0.0,
         "tags":{  
            "Id":"100"
         }
      }
   ]
}

---

验证Json后，我为什么看不到任何问题？我找到了问题的原因和所在。事实上，我从Kafka获取的值是Json，但Json包含额外的转义字符，如下所示：

"{\"fromSource\":\"kafkaProducer\",\"dataPoints\":

我不得不做额外的解析来取消转义字符