Scala -如何获取Json字段的最大值？

libraryDependencies += "com.typesafe.play" %% "play-json" % "2.9.2"

import play.api.libs.json._
import play.api.libs.functional.syntax._

val json: JsValue = Json.parse("""{"field1": 10, "field2": 20, "field3": 30}""")
val field1Value: Option[Int] = (json \ "field1").validate[Int].asOpt

val field1Value: Option[Int] = (json \ "field1").validate[Int].asOpt
val field2Value: Option[Int] = (json \ "field2").validate[Int].asOpt
val field3Value: Option[Int] = (json \ "field3").validate[Int].asOpt

val maxValue: Option[Int] = List(field1Value, field2Value, field3Value).flatten.fold(Option.empty[Int])((max, value) => max.map(math.max(_, value)).orElse(Some(value)))