播放ScalaJSON读取[T]解析ValidationError(error.path.missing,WrappedArray())

时间:2014-02-12 19:37:31

标签: json scala playframework

我有一个有趣的json数据看起来像:

[ {
  "internal_network" : [ {
    "address" : [ {
      "address_id" : 2,
      "address" : "172.16.20.1/24"
    }, {
      "address_id" : 1,
      "address" : "172.16.30.30/24"
    } ]
  } ],
  "switch_id" : "0000000000000001"
}, {
  "internal_network" : [ {
    "address" : [ {
      "address_id" : 2,
      "address" : "172.16.30.1/24"
    }, {
      "address_id" : 1,
      "address" : "192.168.10.1/24"
    }, {
      "address_id" : 3,
      "address" : "172.16.10.1/24"
    } ]
  } ],
  "switch_id" : "0000000000000002"
} ]

我写了案例类和自定义读物:

  case class TheAddress(addr: (Int, String))
  implicit val theAddressReads: Reads[TheAddress] = (
    (__ \ "address_id").read[Int] and
      (__ \ "address").read[String] tupled) map (TheAddress.apply _)

  case class Addresses(addr: List[TheAddress])
  implicit val addressesReads: Reads[Addresses] =
    (__ \ "address").read(list[TheAddress](theAddressReads)) map (Addresses.apply _)

  case class TheSwitch(
    switch_id: String,
    address: List[Addresses] = Nil)
  implicit val theSwitchReads: Reads[TheSwitch] = (
    (__ \ "switch_id").read[String] and
    (__ \ "internal_network").read(list[Addresses](addressesReads)))(TheSwitch)

  case class Switches(col: List[TheSwitch])
  implicit val switchesReads: Reads[Switches] = 
    (__ \ "").read(list[TheSwitch](theSwitchReads)) map (Switches.apply _)

当我用以下方式验证提供的数据时:

val json: JsValue = Json.parse(jsonChunk)
println(json.validate[TheSwitch])

我得到:

JsError(List((/switch_id,List(ValidationError(error.path.missing,WrappedArray()))), (/internal_network,List(ValidationError(error.path.missing,WrappedArray())))))

我可以使用像

这样的JsPath访问它
val switches: Seq[String] = (json \\ "switch_id").map(_.as[String])

但我真的在我的智慧结束,我在做自定义读取时做错了什么。 我已经尝试过放入另一个顶级键和其他组合,但似乎我错过了一些至关重要的东西,因为我刚刚开始使用它。

非常感谢。

1 个答案:

答案 0 :(得分:13)

错误告诉您,而不是/switch_id它有一个数组。因此,您似乎应该将JSON视为List[Switch],而不仅仅是Switch

假设你的Reads(没有测试它们)是正确的,这应该有效:

val json: JsValue = Json.parse(jsonChunk)
println(json.validate[List[TheSwitch]])