Parse Nested JSON Array from Notification Data using Gson in Android

Question

I am getting data in JSON format from FCM notification. It has different format based on notification types as below:

Format 1: accept_request:

Answer 1

It is simple, you should just have an abstract Notification object with the attributes alert, title and notification_type. And then, have specific implementations based on your possible types, so far:

• AcceptRequestNotification extends Notification with just an int booking_id (this is the one you already have, the one you called CommonNotificationBean)
• EndRequestNotification extends Notification which contains for example, an ArrayList called servicesList, this ArrayList should be of type Service and then, service would have the attributes: service_id, service_name, status, sub_category which is again another ArrayList of a custom type.

And then you just change your code to be:

// Check if message contains a data payload.
if (remoteMessage.getData().size() > 0) {
    Log.d(TAG, "Message data payload: " + remoteMessage.getData().get("notification_type"));
    Map params = remoteMessage.getData();

    JSONObject object = new JSONObject(params);

    Gson gson = new Gson();
    JsonReader reader = new JsonReader(new StringReader(object.toString()));
    reader.setLenient(true);

    Class typeOf;

    switch(remoteMessage.getData().get("notification_type")) {
        case "accept_request":
            typeOf = AcceptRequestNotification.class;
        break;
        case "end_request":
            typeOf = EndRequestNotification.class;
        break;
    }

    //you can cast this object later on (to the corresponding custom subclass of Notification), based on the notif.getNotificationType() value.
    Notification notif = gson.fromJson(reader, typeOf);

    sendNotification(notif);
}