GSON not Parsing Nested JSON Object to a value - json

Question

Hello I am using GSON to parse a route object, which contains the following JSON:
{
"mapOverlays": [
{
"id": 1,
"route": 73,
"url": "https://en.wikiarquitectura.com/wp-content/uploads//2017/01/White_House_distr_2C2BA.png",
"lat": 0.00,
"lng": 0.00,
"width": 2000,
"height": 1335,
"scale": 1,
"constraints": {
"w": [
0.00,
0.00
],
"x": [
0.00,
0.00
],
"y": [
0.00,
0.00
]
},
"flags": ""
}
]
}
The issue is when I try to access the JsonObject of constraints, I get an empty JSONObject.
Here is the Data model class of the Basemaps.
import com.google.gson.JsonObject
import com.travelstorysgps.travelstoryssdk.extensions.md5
import java.io.Serializable
class Basemap (
val id: Int,
val route: Int,
val url: String,
val lat: Double,
val lng: Double,
val width: Int,
val height: Int,
val scale: Double,
val constraints : JsonObject ,
val flags: String
) : Serializable {
val filename: String
get() = url.md5() + ".file"
}
And this is the output I get when I call Basemap.constraints : I/System.out: [BASEMAP]: {} It should contain JSONArrays named w,x, and y.
Is there something wrong with my Data model class?
EDIT: Here is the parent Route object:
package com.travelstorysgps.travelstoryssdk.data.model
import android.content.Context
import com.travelstorysgps.travelstoryssdk.data.Location
import java.io.Serializable
import java.util.*
import kotlin.math.floor
data class Route(
val route: RouteDefinition,
val tracks: List<Track>,
val geotags: List<Geotag>,
val images: List<Image>,
val music: List<Music>,
val assets: AssetList,
val orgs: List<Organization>,
val mapOverlays: List<Basemap>,
val ecoupons: List<Coupon>,
var distance: Int,
var routeKey: String = "",
var isDownloading: Boolean = false
) : Serializable {
val artists: List<Int>
get() = music.map { it.artist }.distinct()
}```

Answer 1

The Basemap object is wrapped in parent JSON object under mapOverlays array field. You need an additional class to deserialize in proper structure.
data class Parent(val mapOverlays: List<Basemap>)
fun someFn(json: String) {
val parent = Gson().fromJson(json, Parent::class.java)
println(parent.mapOverlays[0].constraints)
}