`Map [String,String]`别名的NotSerializableException

Question

我正在尝试将对象发送给远程actor,我得到了这个异常:

ERROR akka.remote.EndpointWriter - Transient association error (association remains live)
java.io.NotSerializableException: scala.collection.immutable.MapLike$$anon$2

被序列化的对象是一个案例类:

case class LocationReport(idn: String, report: String, timestamp: Option[String], location: Attr, status: Attr, alarms: Attr, network: Attr, sensors: Attr) extends Message(idn) {

  val ts = timestamp getOrElse location("fix_timestamp")

  def json =
    (report ->
      ("TIME" -> ts) ~
      ("location" -> location) ~
      ("alarms" -> alarms) ~
      ("network" -> network) ~
      ("sensors" -> ((status ++ sensors) + ("CUSTOMCLOCK" -> Report.decodeTimestamp(ts)))))
}

并且Attr是一种类型重新定义:

type Attr = Map[String, String]

这Message堂课非常简单:

abstract class Message(idn: String) {
  def topic = idn
  def json(): JValue
}

我想知道类型别名/重定义是否混淆了序列化器.我想我正在使用ProtoBuf序列化,但我确实JavaSerializer在堆栈跟踪中看到了.

更多调试信息

我新建了一个JavaSerializer并单独序列化了每个地图.只有一个(alarms)无法序列化.这是每个的toString:

这个失败了:

alarms = Map(LOWBATTERY -> 1373623446000)

这些成功了:

location = Map(a_value -> 6, latitude -> 37.63473, p_value -> 4, longitude -> -97.41459, fix_timestamp -> 3F0AE7FF, status -> OK, fix_type -> MSBL, CUSTOMCLOCK -> 1373644159000)
network = Map(SID -> 1271, RSSI -> 85)
sensors = Map(HUMIDITY -> -999, PRESSURE -> -999, LIGHT -> -999  9:52 AM)
status = Map(TEMPERATURE_F -> 923, CYCLE -> 4, TEMPERATURE1_C -> 335, CAP_REMAINING -> 560, VOLTAGE -> 3691, CAP_FULL -> 3897)

Answer 1

问题是Map.mapValues产生一个不可序列化的对象.当警报创建时,它会运行类似的东西alarms.mapValues(hex2Int).这里描述了问题和解决方法:

https://issues.scala-lang.org/browse/SI-7005

简而言之,解决方案就是这样做 alarms.mapValues(hex2Int).map(identity)