多个 Firebase 数据库子/值侦听器对移动应用程序是否有效？

Question

I've been reading about Firebase Realtime Database for a while now I'm just wondering about the whole idea of event-driven data fetching from database. If data is downloaded from the database only when there was a change made to it, then it should be much less demanding on the device resources like battery or Internet connection. I thought I could remap the whole database fragment I need in my Android activity with my model objects that reflect the structure of my database and update its values with Child/Value listeners. Then I would have the whole data I need in a flexible form of POJOs and it would update every time there was a change in the database. So it is actually a real-time solution. But I wonder if such number of listeners would slow down or overload user's device in any terms like battery life or data transfer.

So, would It be a good solution to reflect database state in my Java model objects or should I go another way?

Could anyone resolve my doubts? Thanks!

Answer 1

The listeners are triggered only when something is changed in the database. So you get data only when needed. It is expected that your app will lose their socket connections when there is no visible activity. That's the way the Firebase SDK works. Also, Android will aggressively pause background applications so they don't consume data and battery when the user isn't actively using it.

When you restart an activity for example, the Firebase SDK attempts to restore the websocket that it uses to communicate with the server. This websocket is fully managed by the SDK.

Hope it helps.

Answer 2

Firebase.addvalueeventlistener() only work when there is any change or update in database you are requesting. And it is a good way to move with JAVA objects or you can also use HashMaps<>. As far as there is concern for device battery and performance then instead of requesting whole database you try to get only that part whose change event you wanna track. And if you also want to have grabbing data on background as Whatsapp you can you Broadcast Receiver for internet and startservice() for where Firebase.addvalueeventListener() used.