How to parse JSON indexed dictionnary in Kotlin

Question

I am trying to parse JSON with Kotlin. As I am a beginner in Kotlin, this is still a little bit difficult.

Here is my Json example :

"orders": {
  "id" = 1;
  "base_order": {
    "id" = 1;
    "price" = 10;
  }
  "picks": {
    "0": {
      "name": "Omelette du fromage"
    }
    "1": {
      "name": "Baguette"
    }
  }
}

So here is how I am trying to parse that :

@Parcel
class Orders {
  var id = 0L
  var baseOrder = BaseOrder()
  var picks = ArrayList<Picks>()
  
  fun loadFromJson(json: JsonObject) {
    id = readLong(json, TAG_ID)
    json.get(TAG_BASE_ORDER)?.let {
      if (it.isJsonObject)
        baseOrder.loadFromJson(it.asJsonObject)
    }
  }
  
  companion object {
    private const val TAG_ID = "id"
    private const val TAG_BASE_ORDER = "base_order"
  }
}

Here is my BaseOrder class :

@Parcel
class BaseOrder {
  var id = 0L
  var price = 0f
  
  fun loadFromJson(json: JsonObject) {
    id = readLong(json, TAG_ID)
    price = readFloat(json, TAG_PRICE)
  }
  
  companion object {
    private const val TAG_ID = "id"
    private const val TAG_PRICE = "price"
  }
}

And finally my Picks class :

@Parcel
class Picks {
  var name = ""
  
  fun loadFromJson(json: JsonObject) {
    name = readString(json, TAG_NAME)
  }
  
  companion object {
    private const val TAG_NAME = "name"
  }
}

I need to parse my "picks" list, ideally in my ArrayList of Picks() but I have no idea how to loop to parse that kind of list with "0", "1", "2"... index keys.

If you think I did not search enough, please give me at least the name of this kind of json list, so I can do better searches.

========================

EDIT :

I finally found out how to do it ! Here is my code :

@Parcel
class Orders {
  var id = 0L
  var baseOrder = BaseOrder()
  var picks = ArrayList<Picks>()
  var pickItem = Picks() // This is a buffer
  
  fun loadFromJson(json: JsonObject) {
    id = readLong(json, TAG_ID)
    json.get(TAG_BASE_ORDER)?.let {
      if (it.isJsonObject)
        baseOrder.loadFromJson(it.asJsonObject)
    }
    // Here I am going to start parsing it :
    json.get(TAG_PICKS)?.let {
      if (it.isJsonObject)
        it.asJsonObject.entrySet().forEach() {
          it.value.let {
            if (it.isJsonObject)
              pickItem.loadFromJson(it.asJsonObject)//I parse the json item in the buffer
              picks.add(pickItem) // I add the buffer into the array at the right place
              pickItem = Picks()  // I re-init the buffer for next loops
          }
        }
    }
  }
  
  companion object {
    private const val TAG_ID = "id"
    private const val TAG_BASE_ORDER = "base_order"
  }
}

It is a little bit dirty, as I am using a buffer and I think I could do without it, but the syntax is here.

As a very beginner in Kotlin, I am open to any suggestions.

Thanks for the people who tried to help me out :)

welcome to kotlin and firebase realtime database ( i pressume ). your problem is your json does not contain any array/list/collection. you were given an object with indexed attributes, and that's quite different. You must transform first your JSONObject to a JSONArray. like here: https://stackoverflow.com/questions/22687771/how-to-convert-jsonobjects-to-jsonarray , or finding a way through retrofit, as others say. — CptEric, Jan 17 '18 at 10:38
check this : it uses gson lib https://stackoverflow.com/a/45605731/5991631 — msdev16, Jan 17 '18 at 10:44
Here is how to parse this JSON with Klaxon: https://pastebin.com/VFCzziHi — Cedric Beust, Jan 18 '18 at 12:43
Problem solved, read the edit ! Thanks for helping me guys ! — Mathieu, Jan 19 '18 at 14:54

How to parse JSON indexed dictionnary in Kotlin

0 Answers0