JSON using GSON-Library: Error Expected BEGIN_OBJECT but was STRING

GSON fails to parse the value of the creationDate field because it does not know how to handle Joda-Time DateTime objects.

Try to register a type adapter for this class using GsonBuilder's registerTypeAdapter method.

Gson gson = new GsonBuilder().registerTypeAdapter(DateTime.class, new JsonDeserializer<DateTime>() {
    @Override
    public DateTime deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
            throws JsonParseException {
        return new DateTime(json.getAsString());
    }
}).create();