自动映射和"隐式转换必须比Any Ref更具体"错误

Question

基于activator-akka-cassandra示例,我正在创建自己的应用程序,将数据保存到cassandra中.

我将数据模型定义如下

import play.api.libs.json.Json

case class Location(lat: Double, long: Double)
object Location {
  implicit def toLocation(lat: Double, long: Double) = Location(lat, long)
}

case class LocationWithTime(location: Location, time: Long)
object LocationWithTime {
  implicit def toLocationWithTime(location: Location, time: Long) = LocationWithTime(location, time)
}

case class Ping(pingUuid: String, senPhoneNumber: String, recPhoneNumber: Set[String], locationWithTime: LocationWithTime)
object Ping {
  implicit val LocationFormat = Json.format[Location]
  implicit val LocationWithTimeFormat = Json.format[LocationWithTime]
  implicit val PingFormat = Json.format[Ping]
}

不幸的是,应该保存数据的代码:

def insertPing(ping: Ping): Unit =
    session.executeAsync(insertPing.bind(ping.pingUuid, ping.senPhoneNumber, ping.recPhoneNumber,
      ping.locationWithTime.location.lat, ping.locationWithTime.location.long, ping.locationWithTime.time))

不编译并返回错误

Error:(24, 38) the result type of an implicit conversion must be more specific than AnyRef
      ping.locationWithTime.location.lat, ping.locationWithTime.location.long, ping.locationWithTime.time))
                                 ^

示例数据模型中的案例类扩展了AnyVal.基于此,我猜想类似的东西也会在我的情况下做到,但我不能这样做,因为ValueClasses只能有一个参数.我该如何解决这个问题？

Answer 1

虽然我不熟悉Cassandra,但我认为你的问题是bind需要Java Object(即AnyRefs),而且lat是scala.Double(即Java double),而不是AnyRef.

您可以通过包装你让这样的scala.Double以s java.lang.Double.

insertPing.bind(ping.pingUuid, ping.senPhoneNumber, ping.recPhoneNumber, new java.lang.Double(ping.locationWithTime.location.lat), new java.lang.Double(ping.locationWithTime.location.long), ping.locationWithTime.time)