So I have a json string which looks like this:
{
"time": 100,
"velocity": 20,
"player": [
{"name": "player1", "strength": 5},
{"name": "play2", "strength": 10}
]
}
Now I am trying to get convert the value of key "player" to a list of map in Scala. So I use:
val parsed: JsValue = Json.parse(JsString)
val players: List[Map[String, String]] = (parsed \ "player").as[List[Map[String, String]]]
And I got JsResultExceptionError and JsonValidationError .
The reason you get this error, is because you are trying to do an invalid cast. The Entry of strength is an int, and not a String. Therefore, you can fix that by calling:
val players: List[Map[String, String]] = (parsed \ "player").as[List[Map[String, Any]]]
Having said that, I prefer working with case classes representing me data.
We can first define a Player, and its format:
case class Player(name: String, strength: Int)
object Player {
implicit val format: OFormat[Player] = Json.format[Player]
}
Now we can define a class for the whole json:
case class Entity(time: Int, velocity: Int, player: Seq[Player])
object Entity {
implicit val format: OFormat[Entity] = Json.format[Entity]
}
And now we can parse it:
val json = Json.parse(jsonString)
json.validate[Entity] match {
case JsSuccess(entity, _) =>
println(entity)
case JsError(_) => ???
}
Code run at Scastie.