Related
I'm targeting sdk version 27 with a minimum version of 19 and trying to get a service that runs continuously in the background. I tried different service start options but it still got killed with the app. I tried using a BroadcastReceiver to start the service when it got killed but that gave me an error saying that the app was in the background and couldn't start a service so I tried using the JobScheduler and that gave me the same error. How is this supposed to be done? For example, if I were making a pedometer app, how could I keep that running in the background?
In oreo release Android defined limits to background services.
To improve the user experience, Android 8.0 (API level 26) imposes
limitations on what apps can do while running in the background.
Still if app need to run its service always, then we can create foreground service.
Background Service Limitations: While an app is idle, there are limits
to its use of background services. This does not apply to foreground
services, which are more noticeable to the user.
So create a foreground service. In which you will put a notification for user while your service is running. See this answer (There are many others)
Now what if you don't want a notification for your service. A solution is for that.
You can create some periodic task that will start your service, service will do its work and stops itself. By this your app will not be considered battery draining.
You can create periodic task with Alarm Manager, Job Scheduler, Evernote-Jobs or Work Manager.
Instead of telling pros & cons of each one. I just tell you best. Work manager is best solution for periodic tasks. Which was introduced with Android Architecture Component.
Unlike Job-Scheduler(only >21 API) it will work for all versions.
Also it starts work after a Doze-Standby mode.
Make a Android Boot Receiver for scheduling service after device boot.
I created forever running service with Work-Manager, that is working perfectly.
Since Android 8.0 many background service limitations have been introduced.
Two solutions:
if you need to get total control of task and execution timing, you have to choose Foreground Service.
Pros: your app will be considered to be alive, then is more unlikely that the os will kill it to free resources.
Cons: your user will always see the Foreground Notification.
if you need to schedule periodically task, then Work Manager (introduced in Google I/O 18) is the best solution. This component choose the best possible scheduler (Jobscheduler, JobDispatcher, AlarmManager..). Keep in mind that work manager APIs are useful only for the tasks that require guaranteed execution and they are deferrable.
Ref: Android Dev Documentation
The only solution I would suggest is using Firebase Cloud Messages.
Or foreground services.
Using BroadcastReciever we can run backgrouund service continuously, but if it will get killed , destroy automatically re-instance the old service instance
When service stops forcefully it will call onDestroy() method, in this case use one receiver and send one broadcast when ever service destroy and restart service again. in thee following method com.android.app is custom action of reciever class which extends BroadcastReciever
public void onDestroy() {
try {
myTimer.cancel();
timerTask.cancel();
} catch (Exception e) {
e.printStackTrace();
}
Intent intent = new Intent("com.android.app");
intent.putExtra("valueone", "tostoreagain");
sendBroadcast(intent);
}
and in onReceive Method
#Override
public void onReceive(Context context, Intent intent) {
Log.i("Service Stoped", "call service again");
context.startService(new Intent(context, ServiceCheckWork.class));
}
In case device is restarted then we have onBootCompleted action for receiver to catch
When you are targeting SdkVersion "O"
In MainActivity.java define getPendingIntent()
private PendingIntent getPendingIntent() {
Intent intent = new Intent(this, YourBroadcastReceiver.class);
intent.setAction(YourBroadcastReceiver.ACTION_PROCESS_UPDATES);
return PendingIntent.getBroadcast(this, 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
}
here we use PendingIntent with BroadcastReceiver and This BroadcastReceiver has already been defined in AndroidManifest.xml.
Now in YourBroadcastReceiver.java class which contains an onReceive() method:
Override
public void onReceive(Context context, Intent intent) {
if (intent != null) {
final String action = intent.getAction();
if (ACTION_PROCESS_UPDATES.equals(action)) {
NotificationResult result = NotificationResult.extractResult(intent);
if (result != null) {
List<Notification> notifications = result.getNotification();
NotificationResultHelper notificationResultHelper = new
NotificationResultHelper(
context, notifications);
// Save the notification data to SharedPreferences.
notificationResultHelper.saveResults();
// Show notification with the notification data.
notificationResultHelper.showNotification();
Log.i(TAG,
NotificationResultHelper.getSavedNotificationResult(context));
}
}
}
}
as you say:
I tried using a BroadcastReceiver to start the service when it got
killed but that gave me an error saying that the app was in the
background and couldn't start a service
in Oreo when you are in background and you want to start a service that service must be a foreground service use this code:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
context.startForegroundService(intent);
} else {
context.startService(intent);
}
if you use this code in Oreo you have a few seconds in onStartCommand to start foreground otherwise your service considered as not responding and may be force close by user (in Android 8 or above)
There is no need to use BroadcastReceiver to start service after it is closed it is enough to just return START_STICKY or START_REDELIVER_INTENT from onStartCommand of your service to restart service after it is closed
A working hack for this is to simply start a foreground service which is only visible for the fraction of a second and starts your background service. In the background service you'd then periodically start the foreground service.
Before I give an example you should really ask yourself if this is the way to go for you, there might be other solutions to given problems (like using JobIntentService etc.); and keep in mind that this is a hack, it might be patched some time around and I'd generally not use it (I tested it with screen off and battery saving enabled though and it stayed alive the whole time - but this might prevent your device from dozing.. again, this is a dirty hack!)
Example:
public class TemporaryForegroundService extends Service {
public static final int NOTIFICATION_ID = 666;
private static Notification notification;
#Override
public void onCreate() {
super.onCreate();
if(notification == null)
notification = new NotificationCompat.Builder(this, NotificationChannels.importantChannel(this)).
setSmallIcon(R.mipmap.ic_launcher).setContentTitle("The unseen blade").setContentText("If you see me, congrats to you.").build();
startForeground(NOTIFICATION_ID, notification);
startService(new Intent(this, PermanentBackgroundService.class));
stopForeground(true);
stopSelf();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_NOT_STICKY;
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
public class PermanentBackgroundService extends Service {
private Runnable keepAliveRunnable = new Runnable() {
#Override
public void run() {
keepServiceAlive();
if(handler != null) handler.postDelayed(this, 15*1000);
}
};
private Handler handler;
public void onCreate(){
handler = new Handler();
handler.postDelayed(keepAliveRunnable, 30* 1000);
}
public void onDestroy() {
super.onDestroy();
keepServiceAlive();
}
private void keepServiceAlive() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
startForegroundService(new Intent(PermanentBackgroundService.this, TemporaryForegroundService .class));
} else {
startService(new Intent(PermanentBackgroundService.this, TemporaryForegroundService .class));
}
}
}
I am starting a service from my main Android activity as follows:
final Context context = base.getApplicationContext();
final Intent intent = new Intent(context, MyService.class);
startService(intent);
When I close the activity page by swiping it out from the recent apps list, the service stops running and restarts after some time. I can't use persistent services with notifications because of my app requirements. How can I make the service NOT restart or shutdown and just keep on running on app exit?
I'm in the same situation, so far I learned when the app is closed the service get closed also because they are in a one thread, so the service should be on another thread in order fot it not to be closed, look into that and look into keeping the service alive with alarm manager here an example http://www.vogella.com/articles/AndroidServices/article.html this way your service won't be shown in notification.
lastly, after all the research I've done I'm coming to realize that the best choice for a long running service is startForeground(), because it is made for that and the system actually deals with your service well.
make you service like this in your Mainifest
<service
android:name=".sys.service.youservice"
android:exported="true"
android:process=":ServiceProcess" />
then your service will run on other process named ServiceProcess
if you want make your service never die :
onStartCommand() return START_STICKY
onDestroy() -> startself
create a Deamon service
jin -> create a Native Deamon process, you can find some open-source projects on github
startForeground() , there is a way to startForeground without Notification ,google it
Services are quite complicated sometimes.
When you start a service from an activity (or your process), the service is essentially on the same process.
quoting from the developer notes
Most confusion about the Service class actually revolves around what it is not:
A Service is not a separate process. The Service object itself does not imply it is running in its own process; unless otherwise specified, it runs in the same process as the application it is part of.
A Service is not a thread. It is not a means itself to do work off of the main thread (to avoid Application Not Responding errors).
So, what this means is, if the user swipes the app away from the recent tasks it will delete your process(this includes all your activities etc).
Now, lets take three scenarios.
First where the service does not have a foreground notification.
In this case your process is killed along with your service.
Second where the service has a foreground notification
In this case the service is not killed and neither is the process
Third scenario
If the service does not have a foreground notification, it can still keep running if the app is closed. We can do this by making the service run in a different process.
(However, I've heard some people say that it may not work. left to you to try it out yourself)
you can create a service in a separate process by including the below attribute
in your manifest.
android:process=":yourService"
or
android:process="yourService" process name must begin with lower case.
quoting from developer notes
If the name assigned to this attribute begins with a colon (':'), a new process, private to the application, is created when it's needed and the service runs in that process. If the process name begins with a lowercase character, the service will run in a global process of that name, provided that it has permission to do so. This allows components in different applications to share a process, reducing resource usage.
this is what I have gathered, if anyone is an expert, please do correct me if I'm wrong :)
This may help you. I may be mistaken but it seems to me that this is related with returning START_STICKY in your onStartCommand() method. You can avoid the service from being called again by returning START_NOT_STICKY instead.
The Main problem is in unable to start the service when app closed, android OS(In Some OS) will kill the service for Resource Optimization, If you are not able to restart the service then call a alarm manger to start the receiver like this,Here is the entire code, This code will keep alive ur service.
Manifest is,
<service
android:name=".BackgroundService"
android:description="#string/app_name"
android:enabled="true"
android:label="Notification" />
<receiver android:name="AlarmReceiver">
<intent-filter>
<action android:name="REFRESH_THIS" />
</intent-filter>
</receiver>
IN Main Activty start alarm manger in this way,
String alarm = Context.ALARM_SERVICE;
AlarmManager am = (AlarmManager) getSystemService(alarm);
Intent intent = new Intent("REFRESH_THIS");
PendingIntent pi = PendingIntent.getBroadcast(this, 123456789, intent, 0);
int type = AlarmManager.RTC_WAKEUP;
long interval = 1000 * 50;
am.setInexactRepeating(type, System.currentTimeMillis(), interval, pi);
this will call reciver and reciver is,
public class AlarmReceiver extends BroadcastReceiver {
Context context;
#Override
public void onReceive(Context context, Intent intent) {
this.context = context;
System.out.println("Alarma Reciver Called");
if (isMyServiceRunning(this.context, BackgroundService.class)) {
System.out.println("alredy running no need to start again");
} else {
Intent background = new Intent(context, BackgroundService.class);
context.startService(background);
}
}
public static boolean isMyServiceRunning(Context context, Class<?> serviceClass) {
ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningServiceInfo> services = activityManager.getRunningServices(Integer.MAX_VALUE);
if (services != null) {
for (int i = 0; i < services.size(); i++) {
if ((serviceClass.getName()).equals(services.get(i).service.getClassName()) && services.get(i).pid != 0) {
return true;
}
}
}
return false;
}
}
And this Alaram reciver calls once when android app is opened and when app is closed.SO the service is like this,
public class BackgroundService extends Service {
private String LOG_TAG = null;
#Override
public void onCreate() {
super.onCreate();
LOG_TAG = "app_name";
Log.i(LOG_TAG, "service created");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(LOG_TAG, "In onStartCommand");
//ur actual code
return START_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
// Wont be called as service is not bound
Log.i(LOG_TAG, "In onBind");
return null;
}
#TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
#Override
public void onTaskRemoved(Intent rootIntent) {
super.onTaskRemoved(rootIntent);
Log.i(LOG_TAG, "In onTaskRemoved");
}
#Override
public void onDestroy() {
super.onDestroy();
Log.i(LOG_TAG, "In onDestroyed");
}
}
From Android O, you cant use the services for the long running background operations due to this, https://developer.android.com/about/versions/oreo/background . Jobservice will be the better option with Jobscheduler implementation.
try this, it will keep the service running in the background.
BackServices.class
public class BackServices extends Service{
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// Let it continue running until it is stopped.
Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
}
}
in your MainActivity onCreate drop this line of code
startService(new Intent(getBaseContext(), BackServices.class));
Now the service will stay running in background.
Using the same process for the service and the activity and START_STICKY or START_REDELIVER_INTENT in the service is the only way to be able to restart the service when the application restarts, which happens when the user closes the application for example, but also when the system decides to close it for optimisations reasons. You CAN NOT have a service that will run permanently without any interruption. This is by design, smartphones are not made to run continuous processes for long period of time. This is due to the fact that battery life is the highest priority. You need to design your service so it handles being stopped at any point.
You must add this code in your Service class so that it handles the case when your process is being killed
#Override
public void onTaskRemoved(Intent rootIntent) {
Intent restartServiceIntent = new Intent(getApplicationContext(), this.getClass());
restartServiceIntent.setPackage(getPackageName());
PendingIntent restartServicePendingIntent = PendingIntent.getService(getApplicationContext(), 1, restartServiceIntent, PendingIntent.FLAG_ONE_SHOT);
AlarmManager alarmService = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
alarmService.set(
AlarmManager.ELAPSED_REALTIME,
SystemClock.elapsedRealtime() + 1000,
restartServicePendingIntent);
super.onTaskRemoved(rootIntent);
}
Why not use an IntentService?
IntentService opens a new Thread apart from the main Thread and works there, that way closing the app wont effect it
Be advised that IntentService runs the onHandleIntent() and when its done the service closes, see if it fits your needs.
http://developer.android.com/reference/android/app/IntentService.html
Best solution is to use the sync Adapter in android to start the service. Create a Sync Adapter and call start service their.. inside onPerformSync method. to create sync Account please refer this link https://developer.android.com/training/sync-adapters/index.html
Why SyncAdapter? Ans: Because earlier you used to start the service using your App context. so whenever your app process get killed (When u remove it from task manager or OS kill it because of lack of resources ) at that time your service will also be removed. SyncAdapter will not work in application thread.. so if u call inside it.. service will no longer be removed.. unless u write code to remove it.
<service android:name=".Service2"
android:process="#string/app_name"
android:exported="true"
android:isolatedProcess="true"
/>
Declare this in your manifest. Give a custom name to your process and make that process isolated and exported .
Running an intent service will be easier. Service in creating a thread in the application but it's still in the application.
Just override onDestroy method in your first visible activity like after splash you have home page and while redirecting from splash to home page you have already finish splash. so put on destroy in home page. and stop service in that method.
I want to show up a Notification when my app is removed from the recent apps list.
I've tried putting code for that in onStop() and onDestroy() but neither works . onStop() is called as soon as the app is closed (though it is still in the recent app list).
Can anyone tell which method is called when app is removed from recent app list or any way in which this need can be accomplished ?
This answer is outdated and most likely will not work on devices with API level 26+ because of the background service limitations introduced in Oreo.
Original answer:
When you swipe an app out of Recents, its task get killed instantly. No lifecycle methods will be called.
To get notified when this happens, you could start a sticky Service and override its onTaskRemoved() method.
From the documentation of onTaskRemoved():
This is called if the service is currently running and the user has
removed a task that comes from the service's application.
For example:
public class StickyService extends Service {
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_STICKY;
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onTaskRemoved(Intent rootIntent) {
Log.d(getClass().getName(), "App just got removed from Recents!");
}
}
Registering it in AndroidManifest.xml:
<service android:name=".StickyService" />
And starting it (e.g. in onCreate()):
Intent stickyService = new Intent(this, StickyService.class);
startService(stickyService);
If my app is running and I press home button, the app goes in background. Now if I long press the home button and kill the app by swiping it from the recent app list, none of the events like onPause(), onStop() or onDestroy() gets called rather the process is terminated.
So if i want my services to stop, kill notifications and unregister listeners, how can I do that?
I just resolved a similar kind of issue.
Here is what you can do if its just about stopping service when application is killed by swiping from Recent app list.
Inside your Manifest file, keep flag stopWithTask as true for Service. Like:
<service
android:name="com.myapp.MyService"
android:stopWithTask="true" />
But as you say you want to unregister listeners and stop notification etc, I would suggest this approach:
Inside your Manifest file, keep flag stopWithTask as false for Service. Like:
<service
android:name="com.myapp.MyService"
android:stopWithTask="false" />
Now in your MyService service, override method onTaskRemoved. (This will be fired only if stopWithTask is set to false).
public void onTaskRemoved(Intent rootIntent) {
//unregister listeners
//do any other cleanup if required
//stop service
stopSelf();
}
Refer my question for more details, which contains other part of code, too.
We need to create a service that would clear the application from recent service
public class ClearService extends Service {
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.d("ClearService", "Service Started");
return START_NOT_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
Log.d("ClearService", "Service Destroyed");
}
#Override
public void onTaskRemoved(Intent rootIntent) {
Log.e("ClearService", "END");
//Code here
stopSelf();
}
}
register this service in manifest.xml
<service android:name="com.package.ClearService" android:stopWithTask="false" />
Then start this service on your splash activity
startService(new Intent(getBaseContext(), ClearService.class));
And now whenever you will clear your app from android recent Then this method onTaskRemoved() will execute.
I resolved similar issue. If you want after swiping from recent task and on next launch it to behave properly then follow below steps:-
1) Save process ID in shared preference:
SharedPreferencesUtils.getInstance().putInt(SharedPreferencesUtils.APP_PROCESS_ID, android.os.Process.myPid());
2) When application is launched from launcher after clear from recent task then do:
int previousProcessID = mSharedPreferencesUtils.getInt(SharedPreferencesUtils.APP_PROCESS_ID);
int currentProcessID = android.os.Process.myPid();
if ((previousProcessID == currentProcessID)) {
// This ensures application not killed yet either by clearing recent or anyway
} else {
// This ensures application killed either by clearing recent or by anyother means
}
When you press home - onPause and onStop of your Activity is being called, so at this time you have to do all savings and cleanup, because Android platform doesn't further guarantee that onDestroy or any other lifecycle method would be invoked, so the process could be killed without any notification.
ViewModel.onCleared() can be useful, if the goal is to release some resource (perhaps a system running somewhere else on the network) when the user executes a surprise exit by swiping, rather than by pressing the "stop" or button. [This is how I originally arrived at this question].
Application doesn't get a notification, and Activity.onDestroy() gets called for configuration changes such as changes in orientation, so the answer isn't there. But ViewModel.onCleared gets called when the Application is swiped away (as well as when the user backs out of the activity). If the resource you want to use is associated with more than one activity in the stack, you can add reference counts or some other mechanism to decide if ViewModel.onClear should release the resource.
This is yet another of many good reasons to use ViewModel pattern
I don't really know why the above approaches are not working on my case even I set android:stopWithTask="false" that onTaskRemoved() not called.
Another good approach would be using AndroidViewModel. This one even works on the case when user exits the applcation on pressing back button.
Just bound ViewModel class to your MainActivity then do your task onCleared() callback.
Example:
public class MainViewModel extends AndroidViewModel {
public MainViewModel(#NonNull Application application) {
super(application);
}
#Override
protected void onCleared() {
// Do your task here
Log.e("MainViewModel", "OnCleared mainViewModel");
super.onCleared();
}
}
then bound it to your MainActivity:
MainViewModel viewModel = new ViewModelProvider(this).get(MainViewModel.class);
~ Voila!
As Bob Cram mentioned in his answer, View Model's onCleared() method is the answer.
It works in both cases :
When the user removes the app by swiping the app from background.
When the user clear all the app using the clear list button.
Service's onTaskRemoved() will work when the user swipes the app from the background, but will not work when the apps are cleared using the kill all button.
But the viewModel's onCleared() method works in both cases. You can use if to stop any ongoing process or clearing any task in the remote server.
override fun onCleared() {
super.onCleared()
Log.d(TAG , "App Killed")
}
You need to save your data when on onPause() is called.
Look at this life cycle diagram:
Android Developer
You can see that an app can be killed after onPause() or onStop().
Handle your data there and recover it in onRestart() \ onCreate().
good luck!
This worked for me on android 6,7,8,9.
Make one service like this:
public class OnClearFromRecentService extends Service {
#Override public IBinder onBind(Intent intent) {
return null; }
#Override public int onStartCommand(Intent intent, int flags, int
startId) {
Log.d("ClearFromRecentService", "Service Started");
return START_NOT_STICKY; }
#Override public void onDestroy() {
super.onDestroy();
Log.d("ClearFromRecentService", "Service Destroyed"); }
#Override public void onTaskRemoved(Intent rootIntent) {
Log.e("ClearFromRecentService", "END");
//Code here
stopSelf(); } }
2) Register this service in manifest.xml:
<service android:name="com.example.OnClearFromRecentService"
android:stopWithTask="false" />
3) Then start this service on your splash activity
startService(new Intent(getBaseContext(),
OnClearFromRecentService.class));
I am starting a service from my main Android activity as follows:
final Context context = base.getApplicationContext();
final Intent intent = new Intent(context, MyService.class);
startService(intent);
When I close the activity page by swiping it out from the recent apps list, the service stops running and restarts after some time. I can't use persistent services with notifications because of my app requirements. How can I make the service NOT restart or shutdown and just keep on running on app exit?
I'm in the same situation, so far I learned when the app is closed the service get closed also because they are in a one thread, so the service should be on another thread in order fot it not to be closed, look into that and look into keeping the service alive with alarm manager here an example http://www.vogella.com/articles/AndroidServices/article.html this way your service won't be shown in notification.
lastly, after all the research I've done I'm coming to realize that the best choice for a long running service is startForeground(), because it is made for that and the system actually deals with your service well.
make you service like this in your Mainifest
<service
android:name=".sys.service.youservice"
android:exported="true"
android:process=":ServiceProcess" />
then your service will run on other process named ServiceProcess
if you want make your service never die :
onStartCommand() return START_STICKY
onDestroy() -> startself
create a Deamon service
jin -> create a Native Deamon process, you can find some open-source projects on github
startForeground() , there is a way to startForeground without Notification ,google it
Services are quite complicated sometimes.
When you start a service from an activity (or your process), the service is essentially on the same process.
quoting from the developer notes
Most confusion about the Service class actually revolves around what it is not:
A Service is not a separate process. The Service object itself does not imply it is running in its own process; unless otherwise specified, it runs in the same process as the application it is part of.
A Service is not a thread. It is not a means itself to do work off of the main thread (to avoid Application Not Responding errors).
So, what this means is, if the user swipes the app away from the recent tasks it will delete your process(this includes all your activities etc).
Now, lets take three scenarios.
First where the service does not have a foreground notification.
In this case your process is killed along with your service.
Second where the service has a foreground notification
In this case the service is not killed and neither is the process
Third scenario
If the service does not have a foreground notification, it can still keep running if the app is closed. We can do this by making the service run in a different process.
(However, I've heard some people say that it may not work. left to you to try it out yourself)
you can create a service in a separate process by including the below attribute
in your manifest.
android:process=":yourService"
or
android:process="yourService" process name must begin with lower case.
quoting from developer notes
If the name assigned to this attribute begins with a colon (':'), a new process, private to the application, is created when it's needed and the service runs in that process. If the process name begins with a lowercase character, the service will run in a global process of that name, provided that it has permission to do so. This allows components in different applications to share a process, reducing resource usage.
this is what I have gathered, if anyone is an expert, please do correct me if I'm wrong :)
This may help you. I may be mistaken but it seems to me that this is related with returning START_STICKY in your onStartCommand() method. You can avoid the service from being called again by returning START_NOT_STICKY instead.
The Main problem is in unable to start the service when app closed, android OS(In Some OS) will kill the service for Resource Optimization, If you are not able to restart the service then call a alarm manger to start the receiver like this,Here is the entire code, This code will keep alive ur service.
Manifest is,
<service
android:name=".BackgroundService"
android:description="#string/app_name"
android:enabled="true"
android:label="Notification" />
<receiver android:name="AlarmReceiver">
<intent-filter>
<action android:name="REFRESH_THIS" />
</intent-filter>
</receiver>
IN Main Activty start alarm manger in this way,
String alarm = Context.ALARM_SERVICE;
AlarmManager am = (AlarmManager) getSystemService(alarm);
Intent intent = new Intent("REFRESH_THIS");
PendingIntent pi = PendingIntent.getBroadcast(this, 123456789, intent, 0);
int type = AlarmManager.RTC_WAKEUP;
long interval = 1000 * 50;
am.setInexactRepeating(type, System.currentTimeMillis(), interval, pi);
this will call reciver and reciver is,
public class AlarmReceiver extends BroadcastReceiver {
Context context;
#Override
public void onReceive(Context context, Intent intent) {
this.context = context;
System.out.println("Alarma Reciver Called");
if (isMyServiceRunning(this.context, BackgroundService.class)) {
System.out.println("alredy running no need to start again");
} else {
Intent background = new Intent(context, BackgroundService.class);
context.startService(background);
}
}
public static boolean isMyServiceRunning(Context context, Class<?> serviceClass) {
ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningServiceInfo> services = activityManager.getRunningServices(Integer.MAX_VALUE);
if (services != null) {
for (int i = 0; i < services.size(); i++) {
if ((serviceClass.getName()).equals(services.get(i).service.getClassName()) && services.get(i).pid != 0) {
return true;
}
}
}
return false;
}
}
And this Alaram reciver calls once when android app is opened and when app is closed.SO the service is like this,
public class BackgroundService extends Service {
private String LOG_TAG = null;
#Override
public void onCreate() {
super.onCreate();
LOG_TAG = "app_name";
Log.i(LOG_TAG, "service created");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(LOG_TAG, "In onStartCommand");
//ur actual code
return START_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
// Wont be called as service is not bound
Log.i(LOG_TAG, "In onBind");
return null;
}
#TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
#Override
public void onTaskRemoved(Intent rootIntent) {
super.onTaskRemoved(rootIntent);
Log.i(LOG_TAG, "In onTaskRemoved");
}
#Override
public void onDestroy() {
super.onDestroy();
Log.i(LOG_TAG, "In onDestroyed");
}
}
From Android O, you cant use the services for the long running background operations due to this, https://developer.android.com/about/versions/oreo/background . Jobservice will be the better option with Jobscheduler implementation.
try this, it will keep the service running in the background.
BackServices.class
public class BackServices extends Service{
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// Let it continue running until it is stopped.
Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
}
}
in your MainActivity onCreate drop this line of code
startService(new Intent(getBaseContext(), BackServices.class));
Now the service will stay running in background.
Using the same process for the service and the activity and START_STICKY or START_REDELIVER_INTENT in the service is the only way to be able to restart the service when the application restarts, which happens when the user closes the application for example, but also when the system decides to close it for optimisations reasons. You CAN NOT have a service that will run permanently without any interruption. This is by design, smartphones are not made to run continuous processes for long period of time. This is due to the fact that battery life is the highest priority. You need to design your service so it handles being stopped at any point.
You must add this code in your Service class so that it handles the case when your process is being killed
#Override
public void onTaskRemoved(Intent rootIntent) {
Intent restartServiceIntent = new Intent(getApplicationContext(), this.getClass());
restartServiceIntent.setPackage(getPackageName());
PendingIntent restartServicePendingIntent = PendingIntent.getService(getApplicationContext(), 1, restartServiceIntent, PendingIntent.FLAG_ONE_SHOT);
AlarmManager alarmService = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
alarmService.set(
AlarmManager.ELAPSED_REALTIME,
SystemClock.elapsedRealtime() + 1000,
restartServicePendingIntent);
super.onTaskRemoved(rootIntent);
}
Why not use an IntentService?
IntentService opens a new Thread apart from the main Thread and works there, that way closing the app wont effect it
Be advised that IntentService runs the onHandleIntent() and when its done the service closes, see if it fits your needs.
http://developer.android.com/reference/android/app/IntentService.html
Best solution is to use the sync Adapter in android to start the service. Create a Sync Adapter and call start service their.. inside onPerformSync method. to create sync Account please refer this link https://developer.android.com/training/sync-adapters/index.html
Why SyncAdapter? Ans: Because earlier you used to start the service using your App context. so whenever your app process get killed (When u remove it from task manager or OS kill it because of lack of resources ) at that time your service will also be removed. SyncAdapter will not work in application thread.. so if u call inside it.. service will no longer be removed.. unless u write code to remove it.
<service android:name=".Service2"
android:process="#string/app_name"
android:exported="true"
android:isolatedProcess="true"
/>
Declare this in your manifest. Give a custom name to your process and make that process isolated and exported .
Running an intent service will be easier. Service in creating a thread in the application but it's still in the application.
Just override onDestroy method in your first visible activity like after splash you have home page and while redirecting from splash to home page you have already finish splash. so put on destroy in home page. and stop service in that method.