Long running service to receive push messages from emqx

Question

I want to implement a long running service to receive push messages from emqx server (even when the program is not running). If I use android Service or JobIntentService, it will be necessary to display a notification which is not intended. If I use WorkManager, The minimum repeat interval that can be defined is 15 minutes. For some reason we do not want to use Firebase. Is there a solution to this issue?

Answer 1

"Push Notification" means "the server triggers your App", so there are two main methods:

1. use native Android Firebase Messagging create
2. a persistent connection between all Clients and your Server

First option uses a single connection which is managed by Android for all (or most of) Apps, so the energy compsumption is very low and Connection/Network events are managed by Android itself.

The Second option requires heavy work about Connection/Network re-connections and some work on Server-side. Your server should hold and manage many Client connections for how log it's needed. Moreover the Server should know Client's TCP/UDP handler to know which Client to send message at. This way drains more battery energy than the first one.

If you intend "Push Notification" as "polling the Server to know if some Notification is ready", then you're misunderstooding "Push" word and you can ONLY create a persistant Service WITH notification icon (this behaviour is mandatory starting from SDK 26).

Answer 2

As you mentioned, in new versions of android, there are many restriction on using background services. Therefore, I suggest you using a hybrid approach if you can. Your server informs the client for new messages using google-fcm service and whenever the client received it, on WorkManager establish a connection to the emqx broker in order to get the actual messages. In this approach you can connect to your broker whenever the app is on the foreground and also you do not send your messages through the fcm but using it as an alarm to clients for new messages.