PlayFrameworkJson中的动态Json值-DynamicJsonvaluesinPlayFrameworkJson

2  

Only very little is needed to be changed in your impl. You need to read the field "gps" as something that is 'safe' like JsValue and then try to map it into your GPS case class if it can be done, if not, return None.

只需要很少的东西就可以在你的impl中改变。您需要将“gps”字段读作“JsValue”之类的“安全”字段，然后尝试将其映射到GPS案例类中，如果可以，则返回“无”。

case class GPS(a:String, b:String)
object GPS {
  val travelInfoReads = Json.reads[GPS]
  val travelInfoWrites = Json.writes[GPS]
  implicit val travelInfoFormat: Format[GPS] = Format(travelInfoReads, travelInfoWrites)
}
case class Address(address: String,
                   gps: Option[GPS],
                   country: String) {}

object Address {
  implicit val reads: Reads[Address] = (
    (JsPath \ "address").read[String] and
      (JsPath \ "gps").read[JsValue].map(js => js.asOpt[GPS]) and
      (JsPath \ "country").read[String]
    ) (Address.apply _)

  implicit val writes: Writes[Address] = (
    (JsPath \ "address").write[String] and
      (JsPath \ "gps").writeNullable[GPS] and
      (JsPath \ "country").write[String]
    ) (unlift(Address.unapply))
}

I also tested it:

我也测试了它：

val json = Json.toJson(Address("1",Some(GPS("a","b")),"2"))
      println(json)
      println(json.as[Address])
      val newObj: JsObject = (json.as[JsObject] - "gps") + ("gps" -> JsNumber(1))
      println(newObj)
      val a = newObj.as[Address]
      println(a)
      a must beEqualTo(Address("1",None,"2"))

Output was like

输出就像

{"address":"1","gps":{"a":"a","b":"b"},"country":"2"}
Address(1,Some(GPS(a,b)),2)
{"address":"1","country":"2","gps":1}
Address(1,None,2)