can't handle the following json: {"type":"Point","coordinates":[37.43504333,-122.42824554]}

[GoogleCodeExporter]

What steps will reproduce the problem?

url: http://twitter.com/statuses/user_timeline.json?
screen_name=StartupDigest

// get http request, convert to bufferedreader

Type listType = new TypeToken<List<Status>>() {}.getType();
gson.fromJson(bufferedReader, listType);

What is the expected output? What do you see instead?

Expected: A json deserialized object in java.

Actual:

The JsonDeserializer failed to deserialized json object 
{"type":"Point","coordinates":[37.43504333,-122.42824554]}

What version of the product are you using? On what operating system?

Latest.  Windows Vista.

Original issue reported on code.google.com by david.jonathan.nelson on 24 Jan 2010 at 8:54

[GoogleCodeExporter]

The related thread I suppose is here:

http://groups.google.com/group/google-gson/browse_frm/thread/9e654daeda6f4d9a/bb
9ce6f0a8a5708d?#bb9ce6f0a8a5708d

Steps to reproduce:

1. Initial JSON contains array:

  {value1 : "value 1", value2 : ["1", "2"] } 

2. Map doc = gson.fromJson( {value1 : "value 1", value2 : ["1", "2"] },
          new TypeToken<Map<String, Object>>(){}.getType());

java.lang.RuntimeException: com.google.gson.JsonParseException: Type
information is unavailable, and the target object is not a primitive:
["1", "2"]

Thus GSON cannot form a Collection out of JSonArray.
However, in case then JSON is like 

{value1 : "value 1", value2 : {"1", "2"} }

the above exception can be just because no Java type pointed out for {"1", 
"2"}. But
["1", "2"] is a Collection (Of course, not generic collection, so type of its
elements is not known. May in this case cast to String?). 

Original comment by Anton.Troshin@gmail.com on 12 Mar 2010 at 1:42

[GoogleCodeExporter]

You'll need to write a custom serializer. Here's how that looks:

  static class Geo {
    GeoType type;
    double[] coordinates;
  }

  enum GeoType {
    POINT, ADDRESS;
  }

  public static void main(String... args) {
    /*
     * This deserializer turns a "Point" into our GeoType enum.
     * A custom deserializer required because enums are case-sensitive.
     */
    JsonDeserializer<GeoType> geoTypeDeserializer = new JsonDeserializer<GeoType>() {
      public GeoType deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
          throws JsonParseException {
        return GeoType.valueOf(json.getAsString().toUpperCase());
      }
    };

    /*
     * This deserializer turns the full object into an instance of Geo.
     */
    JsonDeserializer<Geo> geoDeserializer = new JsonDeserializer<Geo>() {
      public Geo deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
          throws JsonParseException {
        JsonObject jsonObject = json.getAsJsonObject();
        Geo result = new Geo();
        result.type = context.deserialize(jsonObject.get("type"), GeoType.class);
        result.coordinates = context.deserialize(jsonObject.get("coordinates"), double[].class);
        return result;
      }
    };

    Gson gson = new GsonBuilder()
        .registerTypeAdapter(GeoType.class, geoTypeDeserializer)
        .registerTypeAdapter(Geo.class, geoDeserializer)
        .create();

    String json = "{\"type\":\"Point\",\"coordinates\":[37.43504333,-122.42824554]}";
    Geo geo = gson.fromJson(json, Geo.class);
    System.out.println(geo.type + " " + Arrays.toString(geo.coordinates));
  }

Original comment by limpbizkit on 28 Aug 2010 at 5:23

• Changed state: Invalid

[GoogleCodeExporter]

Custom serializer is okey, but what we really asked for is GSON to be able to 
deal with ARRAYS of primitives.

Original comment by Anton.Troshin@gmail.com on 28 Aug 2010 at 7:13

[GoogleCodeExporter]

Yes, It does not solve our problem. We need it auto cast to string of array.

Original comment by laise...@gmail.com on 4 Jun 2011 at 3:41