In several apps we use local services to (for example) record locations. This is working perfect for some time (e.g. 4 hours or 150km) and then Android closes (no longer wants) the service. The service is not crashing it's Android that decides to close the service.
It's written in the docs and it's ok BUT I need to find out that a service has been closed. How can I do that?
I would like to restart our service as soon as possible. How do you guys find out that a service has been closed by Android? Do you use finalize?
Thanks in advance.
Have you tried to return Service.START_STICKY or Service.START_REDELIVER_INTENT from Service.onStartCommand() method?
Your service's onDestroy method should be called as it is destroyed by Android OS. Also you should see in logs that normally android re-boots your service after a short time period, which is shown in the logs as it is destroyed, in my experience its around 15-30 seconds before it is booted again. (Every service you have in your app will be booted in a random order so beware if some services rely on other services in your app.)
Related
I'm creating an app that captures location every 30 seconds. To do so, I've a foreground service and a handler in it that gets the latest location every 30 seconds. The app is working just fine for many devices with stock OS. But, on some devices like OnePlus, Panasonic, Vivo etc. the foreground service gets killed by the OS(sometimes the app too) even after changing the battery optimization status and the doze mode. I know that it is not possible to create a service in Android that does not die. Is there any way I can achieve what I'm trying to? Please let me know. Thanks!
First of all, yes you are right the operating system will stop services when resources are limited, so to get around this you state the type of the services while creating them as the following:
START_STICKY, START_NOT_STICKY, START_REDELIVER_INTENT...
read the last part of this article it talks about when to use which of them
https://android-developers.googleblog.com/2010/02/service-api-changes-starting-with.html
Service.onStartCommand() callback that allows the service to better control how the system should manage it. The key part here is a new result code returned by the function, telling the system what it should do with the service if its process is killed while it is running.
my knowledge of services in any operating system, is that they usually run in the background and perform whatever work they have to do.
but the first time I got familiarized with android services, I got confused.
it appears they only run when the application is working, and that for me, makes them no more then sophisticated threads.
do I have this all wrong? how do I make a service that runs when the application doesn't? (so that I can check for updates and create notifications for the user that will then lead him to the application if he chooses to open them).
does push notifications have anything to do with it?
Edit:
thank you guys for your answers so far.
my problem seems to be the fact that the service is only started officialy when the device is booted up. I do call startService when the app starts, but that doesn't seem to help. the service still dies when the app is turned off (unless it was booted)
also I never call stopService
If you are trying to implement a long running task that is performed in a (background) service, you have to start one or more threads within your service. So the service just gives you the opportunity to have an application context without having to have a user interface ;) you can consider it as a kind of container.
This page give you a nice overview about different thread approaches in Android. As you can see a service has not its own thread.
Anyway, in your case it seems that an AlarmManager is probably the better option. Running services for polling information all the time can be quite CPU and battery consuming (see this post for instance). So try to avoid having threads that run all the time.
If you can push information about updates from a server it's just fine. Check out Googles Cloud Messaging in this case.
Michael who commented on my question first was right in his comment about startService()
so it goes like this:
my receiver is only activated on boot, and uses an AlarmManager to
time the service to certain intervals.
what I did was to bind the activities to the service. if the service
was off and I binded it and unbinded it, then by the time the app was
terminated, there was nothing keeping it alive.
by simply making sure that the service was started properly with
startService if it is not already on, I managed to keep the service
alive at all times
also thanks to Trinimon who gave a very nice explanation on what
services are, and the importance of not overloading the CPU with
excessive polling. (which is kind of a trade off situation)
good luck to all :)
I want to ask if Android is firing an event when a process has been started? Or is there any proper way to find out if a process has been started?
I have implemented some basic algorithm of catching when a process of interest has been started but it's working in a service with 5 mins checking if the process is running or not.
My task is finding out when an application is started and stopped and count the time it has been active.
If you only want to know is a app started or not, use ActivityManager.getRunningAppProcesses is enough.
If you need a real-time reporting of a started process, the answer is no, and it is not possible using the current sdk.
You can take some existing approaches on a rooted device.
I did a search before asking so please don't tell me to do that.
I'm relatively new to Android so I get confused easily.
I'm making a simple app that changes the ringer volume according to time. For this purpose, I know I need a service that keeps running in the bg and monitor time. However, I really don't know how to approach this. I have the Professional Android Application Development book but haven't found anything that helps in there.
My question:
How to constantly check time without destroying the battery
If my code is needed (as proof of me actually working on this), I'll post.
You don't need a service. Use the AlarmManager class. Its like an alarm clock and it exactly what you need for this type of app.
need a service that keeps running in the bg and monitor time
No. Actually that's not how to do it. Services on android are different than your normal windows service/unix daemon. They should do their job and then stop themself until they get started again - to save battery.
You should start your service at a certain point in time by using the AlarmManager, it sends the launch intent to run the service. When the service is finished doing what it's supposed to do (change the rintone volume here), use Service.stopSelf() to kill it.
I am making an android app which will have two services that will keep sending data about the usage of the phone by the user every 24 hours.
The user should execute the app, toggle the buttons to enable the logging of the usage of the phone and then the user should be able to do a normal life with his phone, until he starts again the app and disables the toggle button to stop the logging of the info.
What considerations should I take about the life cycle of the services?
What about the interaction of the user with the phone while the services should be sending the data?
All info is very much appreciated, as I my mind is getting a little bit overwhelmed with all this!
Thanks a lot in advance everybody!
The service can be cut at any time through the settings menu. It can also be killed at any time by Android if it decides it needs the resources for the currently running activity. onDestroy() will be called regardless so use that to store anything needed.
The service runs in the background but through the main UI thread. Thus, it is possible to block operation of the phone through a service. It looks like the phone locked up when it's really a service trying to do something. Any blocking procedure should be used in a thread such as Java timer, Java thread, or AsyncTask.
There can only be one running version of the service at any given time. However, calling startService(myService) if "myService" is already running will essentially override the current running service and onStartCommand() will be called again. However, one call to stopService(myService) is needed to stop it no matter how many times startService(myService) was called.
stopService(myService) will not stop a service if the service is bound to anything. It will wait until all bindings are removed before the service stops.