Question

I have a problem creating a mapping for a json that i want to parse using json. It’s very specific, its about a json file with a json array with objects in it.

my jsonfile starts like this:

  [
    {
        "venue": {
            "venue_seasons": [
                {
                    "created_at": "2011-12-25T23:00:28Z",
                    "updated_at": "2011-12-28T15:13:53Z",
                    "start_timestamp": 1293840000,
                    "id": 337,
                    "end": "2011-12-24T00:00:00Z",
                    "enabled": true,
                    "start": "2011-01-01T00:00:00Z",
                    "season_openings": [ … ],
                    "end_timestamp": 1324684800
                },
                { … }
            ],
            "address": "someadress",
            "city": "cityname",
            "name": "name",
            "created_at": "2011-03-31T07:55:33Z",
        etcetera
    }
    "venue":{another venue

So first an array, than an object (venue) with a lot of objects in it (i removed most of them, because thats not important for my question), and some arrays (like season_openings).

My parsing code works like this, im using gson. The inputstream works fine.

Reader reader = new InputStreamReader(inputStream);
JsonResponse venueResponse = gson.fromJson(reader, JsonResponse.class);               
List<Venues> results = venueResponse.venue;

with the class JsonResponse:

public class JsonResponse {
    public List<Venues> venue;  
}

and Venues.class:

public class Venues {

    public List<VenueSeasons> venue_seasons;

    @SerializedName("adress")
    public String getAdress;

    @SerializedName("city")
    public String getCity;

    @SerializedName("country")
    public String getCountry; etcetera 
}

But when i run this code i get an error:

Unable to start activity ComponentInfo{com.hera.android.JSON/com.hera.android.JSON.TestParser2Activity}: com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was BEGIN_ARRAY at line 1 column 2

Ofcourse i can read the error: it expects an objects but get an array. I varied a lot with different jsonresponse.class and even with putting the whole json array in a json object (what is not really a solution because i need to work with this type of jsonfile). But everytime i get this or a similar error.

I think I’m close to a solution, can anyone see what i just can’t and give me a helping hand?
Thanks.

Answer 1

Try calling Gson like this:

List<Venues> venues = gson.fromJson(reader, new TypeToken<List<Venues>>() {}.getType());

This works because your JSON document is a List, not an object that has a list as one of its properties.