gson integer (1) is converted to double (1.0) solution

    private static final Gson gsonInstance;
    static {
        gsonInstance = new GsonBuilder().registerTypeAdapter(Double.class, new JsonSerializer<Double>() {
            @Override
            public JsonElement serialize(Double src, Type typeOfSrc, JsonSerializationContext context) {
                if(src == src.longValue()){
                    return new JsonPrimitive(src.longValue());
                }
                return new JsonPrimitive(src);
            }
        }).create();
    }