CODEWITHSUNDEEP
androidvariablesstaticandroid-serviceforeground
François Dubois
François Dubois

Reputation: 149

Is it a good idea to bind on an Android service in the application class?

I have an Android foreground service that contains a map of session (key, session). In my activities, I receive a key and I want to get the session from the service. So I bind each of my activities to the service and I can ask the service to get my session with my key. But doing this means that I have to wait for onServiceConnected() to get the session.

Is it a good idea to bind the service once in my application class and put my service in a static variable, then all my activities can access the service directly in their onCreate() instead of waiting for the call of onServiceConnected()? But is it sure that my static variable will always be there? Do you know if Android can delete that static variable if it needs resources? I guess the application instance is never deleted, am I right? So it could be a good idea to keep my service in a static variable. What do you think?

Upvotes: 3

Views: 2114

Answers (3)

David Wasser
David Wasser

Reputation: 95618

You can bind to the Service in your Application class. The Application instance is basically a singleton and will live as long as the OS process hosting your app is alive. At some point, Android will kill the OS process hosting your app, and then all your app components will go away (Application instance, Service, Activity instances, etc.). If the user returns to your app, Android will create a new OS process, instantiate a new Application instance and then instantiate your app components as needed.

Upvotes: 1

Perazzo
Perazzo

Reputation: 1147

Application itself doesn't have a lifecycle as other Android components, so if you call bindService() during its onCreate() callback, there is no guaranteed point to call unbindService(), which may lead to memory leaks and unpredictable states. Others have also pointed that here.

Instead, you could start your service in the foreground (displaying a notification like "Remote Desktop Manager is running"), which should keep your app alive, and make the map<key, session> a static variable in your Application. In this way, Activities can retrieve sessions without the connection delay. Just don't forget to stop the service by either calling stopService(Intent intent) or stopSelf() when all sessions get closed.

By the way, it should work even considering background restrictions of Android O.

Upvotes: 0

cutiko
cutiko

Reputation: 10527

What you are trying to do sounds like a dirty implementation of some sort of dispatcher from React, I have being tempt to do it my self, but haven't because of lack of time. Please let us know your results.

I would suggest to use a Messager, the doc have information about it, so no need for static https://developer.android.com/guide/components/bound-services.html?hl=en-419

And yes, Android OS can clean anything, it can kill the service, it can null the variables. Most of the time this doesn't happen because it will be done only to prioritize the foreground app. So if a user opens 10 apps and your is on backgound it probably will. Which seems ok to me. From time to tome I have also experienced variables become null in a Fragment, but then I reduced the variable scope and that fix it.

Also if you are considering this, try with EventBus library or by using ReactJava, maybe Realm ORM or even Firebase could help you.

Upvotes: 1

Related Questions