How to parse below Json data in Kotlin?

Question

I need to parse this information-

[
{
    "artist": "12",
    "image": "23"
},
{
    "video_id": "12",
    "video_title": "23"
},
{
    "video_id": "12",
    "video_title": "23"
},
{
    "video_id": "12",
    "video_title": "23"
},
{
    "video_id": "12",
    "video_title": "23"
},
{
    "video_id": "12",
    "video_title": "23"
}]

As you can see the first field is different, how to parse below information differently and the first field differently in Kotlin.

I am parsing 1st part as-

response ->

                for (i in 0..(response.length() -1)){

                    /**
                        FIRST SONG
                     **/
                    val song = response.get(0).toString()

                    val listOfSongs = response.toString()

                    val parser = Parser()
                    val stringBuilder = StringBuilder(song)
                    val json: JsonObject = parser.parse(stringBuilder) as JsonObject
                    val firstArtist = json.string("artist")
                    val firstImage = json.string("image")
                    val intent = Intent(activity,ResultPage::class.java)
                    intent.putExtra("firstArtist",firstArtist)
                    intent.putExtra("firstImage",firstImage)

                    startActivity(intent)
                    /**
                        FIRST SONG
                    **/


                }
            }

and am also using KLAXON library here.

Answer 1

For your json, this should work :

fun parseResponse(response: String) {

    var artist = ""
    var image = ""
    val videoList = ArrayList<Video>()

    val jsonArray = JSONArray(response)

    (0..5).forEach { index ->
        val jsonObject = jsonArray.getJSONObject(index)
        if (jsonObject.has("artist") && jsonObject.has("image")) {
            artist = jsonObject.getString("artist")
            image = jsonObject.getString("image")
        }
        else if (jsonObject.has("video_id") && jsonObject.has("video_title")) {
            val newVideo = Video(jsonObject.getString("video_id"), jsonObject.getString("video_title"))
            videoList.add(newVideo)
        }
    }
}

class Video(val id: String, val title: String)

But this way is very lengthy and unnecessary. I would suggest use an Object Mapping library like GSON or Moshi.

For that, the video list in your json should ideally be something like:

[
    {
        "artist": "12",
        "image": "23",
        "videos": [
            {
                "video_id": "12",
                "video_title": "23"
            },
            {
                "video_id": "12",
                "video_title": "23"
            },
            {
                "video_id": "12",
                "video_title": "23"
            },
            {
                "video_id": "12",
                "video_title": "23"
            },
            {
                "video_id": "12",
                "video_title": "23"
            }
        ]
    }
]

Using this Json, you can easily create a class for this object, e.g.

class Artist(val id: String, val name: String, val image: String, val videos: List<Video>)
class Video(@field:Json(name = "video_id") val id: String, @field:Json(name = "video_title") val title: String)

And parse them easily like this:

    Moshi.Builder().build().adapter(Artist::class.java).fromJson(response)

and then access this information like:

    val artist = Moshi.Builder().build().adapter(Artist::class.java).fromJson(response)

    intent.putExtra("firstArtist",artist?.name)
    intent.putExtra("firstImage",artist?.image)