使用 GSON 解析复杂 json android

Question

I have json file like

    {
        "type": "Feature",
        "properties": {
          "centlat": -20.63101971,
          "ICAOCODE": "FMMM",
          "REGION": "AFI",
          "FIRname": "FIR ANTANANARIVO",
          "centlong": 48.56534436,
          "StateCode": "MDG",
          "StateName": "Madagascar"
        },
        "geometry": {
          "type": "Polygon",
          "coordinates": [
            [
              [
                57.00000190700007,
                -29.999999999999943
              ],
              [
                57.00000190700007,
                -22.333332061999954
              ],
              [
                55.50000190700007,
                -18.999999999999943
              ],
              [
                55.50000190700007,
                -9.999999999999943
              ],
              [
                45.00000190800006,
                -9.999999999999943
              ],
              [
                44.00000190800006,
                -10.333332060999965
              ],
              [
                41.50000190700007,
                -10.999999999999943
              ],
              [
                43.00000190700007,
                -14.999999999999943
              ],
              [
                40.00000190800006,
                -19.999999999999943
              ],
              [
                40.00000190800006,
                -29.999999999999943
              ],
              [
                57.00000190700007,
                -29.999999999999943
              ]
            ]
          ]
        }
      }

I have installed the plugin robo pogo generator which gave me this output

package com.example.airlineapp.model

import com.google.gson.annotations.SerializedName

data class GeographicalData(

    @field:SerializedName("geometry")
    val geometry: Geometry? = null,

    @field:SerializedName("type")
    val type: String? = null,

    @field:SerializedName("properties")
    val properties: Properties? = null
)

data class Geometry(

    @field:SerializedName("coordinates")
    val coordinates: ArrayList<Double?>? = null,

    @field:SerializedName("type")
    val type: String? = null
)

data class Properties(

    @field:SerializedName("centlong")
    val centlong: Double? = null,

    @field:SerializedName("centlat")
    val centlat: Double? = null,

    @field:SerializedName("FIRname")
    val fIRname: String? = null,

    @field:SerializedName("StateName")
    val stateName: String? = null,

    @field:SerializedName("StateCode")
    val stateCode: String? = null,

    @field:SerializedName("ICAOCODE")
    val iCAOCODE: String? = null,

    @field:SerializedName("REGION")
    val rEGION: String? = null
)

I tried parsing the code but it always shows Expected BEGIN_OBJECT but was BEGIN_ARRAY at line 16 column 10 path $[0].geometry.coordinates[0]

I rectified the issue but the thing is how can I parse this json now with a complex array structure, any suggesstions?

I also tried adding Array of arrays in my POJO classs similar to the struture of json file but that did not worked.

The coordinate array is basically an array of array of arrays, a three level array

Answer 1

Your JSON structure is wrong, instead of this

...
 "coordinates": [
            [
              [
                57.00000190700007,
                -29.999999999999943
              ],
...

you should have this

...
 "coordinates": [
              {
                57.00000190700007,
                -29.999999999999943
              },
...