如何使用Scala删除空的json对象

import play.api.libs.json._

def removeEmptyObjects(json: JsValue): JsValue = {
  json match {
    case obj: JsObject =>
      val updatedFields = obj.fields.flatMap {
        case (key, value) =>
          val updatedValue = removeEmptyObjects(value)
          if (updatedValue != JsNull) Some(key -> updatedValue) else None
      }
      JsObject(updatedFields)
    case arr: JsArray =>
      val updatedValues = arr.value.map(removeEmptyObjects).filter(_ != JsNull)
      JsArray(updatedValues)
    case _ => json
  }
}

val jsonString = """{
  "name": "John",
  "age": null,
  "address": {
    "street": null,
    "city": "New York"
  },
  "friends": [
    {
      "name": "Alice",
      "age": 25,
      "address": null
    },
    {
      "name": "Bob",
      "age": null,
      "address": {
        "street": "123 Main St",
        "city": null
      }
    }
  ]
}"""

val json = Json.parse(jsonString)
val updatedJson = removeEmptyObjects(json)
val result = Json.stringify(updatedJson)

println(result)

{
  "name": "John",
  "address": {
    "city": "New York"
  },
  "friends": [
    {
      "name": "Alice",
      "age": 25
    },
    {
      "name": "Bob",
      "address": {
        "street": "123 Main St"
      }
    }
  ]
}