如何从Scala中的响应JSON中删除List（）并转义字符

Question

I have the following function that takes in a JSON input and validates it against a JSON-Schema using the "com.eclipsesource" %% "play-json-schema-validator" % "0.6.2" library. Everything works fine expect for when I get an invalid JSON, I try to collect all violations into a List and later return that list along with the response JSON. However my List is encoded with List() and also has escape characters. I want to have the response JSON look like this:

{
  "transactionID": "123",
  "status": "error",
  "description": "Invalid Request Received",
  "violations": ["Wrong type. Expected integer, was string.", "Property action missing"]
}

Instead of this: (This is what I am getting right now)

{
  "transactionID": "\"123\"",
  "status": "error",
  "description": "Invalid Request Received",
  "violations": "List(\"Wrong type. Expected integer, was string.\", \"Property action missing\")"
}

And here's the actual function for JSON validation

def validateRequest(json: JsValue): Result = {

    {
      val logger = LoggerFactory.getLogger("superman")
      val jsonSchema = Source.fromFile(play.api.Play.getFile("conf/schema.json")).getLines.mkString
      val transactionID = (json \ "transactionID").get
      val result: VA[JsValue] = SchemaValidator.validate(Json.fromJson[SchemaType](
        Json.parse(jsonSchema.stripMargin)).get, json)

      result.fold(
        invalid = { errors =>

          var violatesList = List[String]()
          var invalidError = Map("transactionID" -> transactionID.toString(), "status" -> "error", "description" -> "Invalid Request Received")
          for (msg <- (errors.toJson \\ "msgs"))
            violatesList = (msg(0).get).toString() :: violatesList
          invalidError += ("violations" -> (violatesList.toString()))
          //TODO: Make this parsable JSON list
          val errorResponse = Json.toJson(invalidError)
          logger.error("""Message="Invalid Request Received" for transactionID=""" + transactionID.toString() + "errorResponse:" + errorResponse)
          BadRequest(errorResponse)

        },

        valid = {
          post =>
            db.writeDocument(json)
            val successResponse = Json.obj("transactionID" -> transactionID.toString, "status" -> "OK", "message" -> ("Valid Request Received"))
            logger.info("""Message="Valid Request Received" for transactionID=""" + transactionID.toString() + "jsonResponse:" + successResponse)
            Ok(successResponse)
        }
      )
    }

  }

UPDATE 1

I get this after using Json.obj()

{
  "transactionID": "\"123\"",
  "status": "error",
  "description": "Invalid Request Received",
  "violations": [
    "\"Wrong type. Expected integer, was string.\"",
    "\"Property action missing\""
  ]
}

Answer 1

What you want is a JSON array, but by calling .toString() on your list, you're actually passing a string. Play has an implicit serializer for List s to JSON arrays, so you actually just have to do less then what you already did - you can just remove the toString() part from violatesList.toString() .

In addition, don't create a map for your JSON and then convert it to a JSON, you can use Json.obj with a very similar syntax instead:

val invalidError = Json.obj("transactionID" -> transactionID, "status" -> "error", "description" -> "Invalid Request Received")
for (msg <- (errors.toJson \\ "msgs"))
  violatesList = (msg(0).get) :: violatesList
val errorResponse = invalidError ++ Json.obj("violations" -> violatesList)

Regarding your escaped quotes, I suppose it's because transactionID and msgs are JsString s, so when you convert them with toString() the quotes are included. Just remove the toString everywhere and you'll be fine.

Answer 2

I got the escape characters removed by modifying this line:

violatesList = (msg(0).get).toString() :: violatesList

TO:

violatesList = (msg(0).get).as[String] :: violatesList