ReactiveMongo + 播放通用 NullPointerException

Question

我正在尝试为我的应用程序整合一个非常简单的 Mongo 模型，但我最初的尝试是徒劳的。我被NullPointerException 卡住了，我什至尝试用Try 结束我的通话并最终得到Success(scala.concurrent.impl.Promise$DefaultPromise@1f02f0b3)

这是代码

  def token = Action.async(parse.json) { request =>
    request.body.validate[Auth].map { creds =>
      UserService.login(creds.username, creds.password).map {
        case Some(context) =>
          val accessToken = TokenResponse(Crypto.generateToken)
          val model = Json.toJson(context)
          val res = Try(collection.insert(model).map(_ => Ok(Json.toJson(accessToken))))
          println(res.toString)
          res.get
        case _ => Future(BadRequest)
      }.flatMap(identity)
    } recoverTotal (request => Future(Unauthorized))
  }

这是错误（注意调用堆栈中没有对我的应用程序的引用）：

play.api.Application$$anon$1: Execution exception[[NullPointerException: null]]
    at play.api.Application$class.handleError(Application.scala:296) ~[play_2.11-2.3.6.jar:2.3.6]
    at play.api.DefaultApplication.handleError(Application.scala:402) [play_2.11-2.3.6.jar:2.3.6]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$3$$anonfun$applyOrElse$4.apply(PlayDefaultUpstreamHandler.scala:320) [play_2.11-2.3.6.jar:2.3.6]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$3$$anonfun$applyOrElse$4.apply(PlayDefaultUpstreamHandler.scala:320) [play_2.11-2.3.6.jar:2.3.6]
    at scala.Option.map(Option.scala:145) [scala-library-2.11.2.jar:na]
Caused by: java.lang.NullPointerException: null
    at reactivemongo.bson.buffer.WritableBuffer$class.writeString(buffer.scala:71) ~[reactivemongo-bson_2.11-0.10.5.0.akka23.jar:0.10.5.0.akka23]
    at reactivemongo.core.netty.ChannelBufferWritableBuffer.writeString(netty.scala:61) ~[reactivemongo_2.11-0.10.5.0.akka23.jar:0.10.5.0.akka23]
    at reactivemongo.bson.buffer.DefaultBufferHandler$BSONStringBufferHandler$.write(bufferhandlers.scala:83) ~[reactivemongo-bson_2.11-0.10.5.0.akka23.jar:0.10.5.0.akka23]
    at reactivemongo.bson.buffer.DefaultBufferHandler$BSONStringBufferHandler$.write(bufferhandlers.scala:82) ~[reactivemongo-bson_2.11-0.10.5.0.akka23.jar:0.10.5.0.akka23]
    at reactivemongo.bson.buffer.DefaultBufferHandler$.serialize(bufferhandlers.scala:227) ~[reactivemongo-bson_2.11-0.10.5.0.akka23.jar:0.10.5.0.akka23]

我尝试使用 Postman，最后得到了这个参考，但没有多大帮助：

app/controllers/Application.scala:27

Answer 1

结果很简单……我生成的 JSON 有空值，而 ReactiveMongo 不喜欢这样。我将提交一个错误以优雅地失败或至少更具描述性。