在Play / Scala中遍歷多個JSON數組

Question

{
    "location":{
        "residents":[{
            "renting":[{
                "name":"John Doe"
                "pets":"2"
            },{
                "name":"Jane Smith"
                "pets":"2"
            }]
        }]
    }
}

我可以成功遍歷位置-

val json = ...

val rentReads = (__ \ 'location).read[String]

val rentResult = json.validate[String](rentReads)

rentResult match {
  case s: JsSuccess[String] => Ok(s.get)
  case e: JsError => Ok("Errors: " + JsError.toFlatJson(e).toString())
}

根據文檔，我應該能夠執行以下操作-

val skillReads = ((__ \ 'location) \ 'residents)(0).read[String]

但它導致以下錯誤-

Errors: {"obj.VariationResultsWrapper.VariationResultSets[0]":[{"msg":"error.path.missing","args":[]}]}

在這一點上，我只是試圖了解如何僅從“租賃”中返回值。 最終，我想將結果映射到案例類。

Answer 1

如果您最終的目標是將其解析為案例類，則只需定義這些案例類，然后讓Play承擔繁重的工作即可。

case class Renting(name: String, pets: String)
case class Resident(renting: List[Renting])
case class Location(residents: List[Resident])

implicit val rentingFormat = Json.format[Renting]
implicit val residentFormat = Json.format[Resident]
implicit val locationFormat = Json.format[Location]

(json \ "location").validate[Location]
res1: play.api.libs.json.JsResult[Location] = JsSuccess(Location(List(Resident(List(Renting(John Doe,2), Renting(Jane Smith,2))))),/residents)