Background: I have a service which register a ContentObserver. ContentObserver should be set even app in not open or device is rebooted. Which can be achieved only by a background service.
Problem: As if Build.VERSION.SDK_INT >= Build.VERSION_CODES.O it can not just start backgroundService. It can only foreground-Service but a foreground service need notification. Which is not good as user will see notification. (Facebook never shows any notification on reboot but still its service get registered)
( Here can be found full code : http://www.digitstory.com/android-detect-new-contact-addition/ with more description that why I am using Handler )
My Service is:-
public class ContactWatchService extends Service {
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
try {
//Register contact observer <--- I register here
} catch (Exception e) {
e.printStackTrace();
}
}
}
#Override
public void onCreate() {
HandlerThread thread = new HandlerThread("ServiceStartArguments", Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
// If we get killed, after returning from here, restart
return START_STICKY;
}
Now on reboot BoradCastReceiver:-
public class MobileRestartReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
context.startService(new Intent(context, ContactWatchService.class)); //TODO--> ERROR won't work as app is in background
}
}
So if I use startForegroundService on MobileRestartReceiver then have to do startForeground(1,notification), which will need notification. (note here u can not just start service it will throw exception that app is in background)
So how I can I registerContentObserver from reboot without showing any notification?
Please care about:Build.VERSION.SDK_INT >= Build.VERSION_CODES.O.
(Manifest is set with all permissions, so don't worry about this)
So how I can I registerContentObserver from reboot without showing any notification?
You can't, sorry. Note, though, that you can use JobScheduler to be notified about changes in a ContentProvider on API Level 24 and higher.
I want to show local notification in an Android app that i am working. notification are based on network transaction completed in background.
I have tried service, intent service, jobservice etc but nothing is working when the app is closed.please share some working code for the reference.....
//Here is my service----
public class JobSyncFAQ extends Service {
private Message msg;
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
public JobSyncFAQ() {
}
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
// here is my stuff
stopSelf(msg.arg1);
}
}
public void onCreate() {
super.onCreate();
HandlerThread thread = new HandlerThread("JobSyncFAQ", Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
mServiceHandler.removeCallbacks(mServiceLooper.getThread());
mServiceLooper.quit();
Intent intent = new Intent(getApplicationContext(),JobSyncFAQ.class);
sendBroadcast(intent);
}
//and in my receiver
public void onReceive(Context context, Intent intent) {
context.startService(new Intent(context, JobSyncFAQ.class));
}
please note - i am facing this issue only for N+ version
When you "close" your app (i. e. you swipe it away on the recent apps screen), you don't actually close the app, you only close the underlying activity. In most cases, this corresponds to the app being closed, but if you have a background service running, the service is not terminated. This is for a good reason: YOu still want to receive WhatsApp messages, even when WhatsApp is closed. Hence, WhatsApp starts a background service to check for new messages, even when the app is closed.
For that reason, you need to notify your background service about the fact that it should cancel its task.
I developed a media application that uses a MediaBrowserService which is connected to a MediaController. Therefore, I can do the following in my activities onDestroyMethod:
MediaControllerCompat mediaControllerCompat = MediaControllerCompat.getMediaController(getActivity());
if (mediaControllerCompat != null)
mediaControllerCompat.getTransportControls().stop();
This tells the MediaBrowserService to stop and quit.
Edit: Since you use a generic service, you need to call stopService:
stopService(new Intent(MyActivity.this, JobSyncFAQ.class));
Im trying to achive, that my service downloads information and fills a database with that information in the background.
SOLUTION (Using foreground service, code is now the edited-version)
Thats the service:
public class UnitPullService extends Service {
private final static String name = UnitPullService.class.getSimpleName();
public static Boolean isRunning = false;
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
try {
UnitDataSource unitdataSource = new UnitDataSource(getApplicationContext());
unitdataSource.fillTables();
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor spEitor = sharedPreferences.edit();
// disables the button which starts this service
spEitor.putBoolean("isFilled", true);
spEitor.commit();
} catch (JSONException e) {
e.printStackTrace();
}
stopSelf(msg.arg1);
}
}
#Override
public void onCreate() {
HandlerThread thread = new HandlerThread("ServiceStartArguments",
Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// PART OF THE SOLUTION
startForeground(1000, new Notification());
Toast.makeText(this, "service starting",
Toast.LENGTH_SHORT).show();
// to check if the service is currently running
isRunning = true;
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
return START_REDELIVER_INTENT;
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
Toast.makeText(this, "service done", Toast.LENGTH_SHORT).show();
}
}
And thats the intent in the activity (actually from a fragment):
Intent i= new Intent(getContext(), UnitPullService.class);
getContext().startService(i);
In the manifest, the service is declared like:
<service
android:name=".UnitPullService"
android:exported="false"/>
The point is, that i want to do the whole "download and database filling"-stuff completly independent from the status of the app which is starting the service (so that the user can use other apps while the service is doing its job).
EDIT (Made false assumptions)
The following behaves weird:
Start application
Start service
Close application (swipe away from running-apps-overview)
Start application before service has finished
"service starting"-toast shows up, handleMessage() gets called and DatabaseErros happening (because of unique constrains, but thats not the point).
the other scenario:
Start application
Start service
Close application (swipe away from running-apps-overview)
fillTables() has finished.
It seems that directly after fillTables() has finished and the service gets restarted (Toast shows up).
Q1: So where is my fault, that the running service is going to restart when I start the application while a running service has not finished yet?
Q1.1: How do i call/create a completly independent service, which does not get restarted in such an anoying way, while doing its job?
Swiping away the app puts it in Force-close state. That kills any services attached to it. It won't allow the service or any other activity in the app to run again until the user has launched it.
Now if the user doesn't swipe away, your service will continue to run no matter what app is in the foreground. And if the service is killed by the OS for resources, you can have it automatically restart when they're available. But nothing will make it run services after being swiped away.
i have created one service by extending Service in android and i am sending Message to service using Messenger and Handler.
But the issue (which is a common behavior though) is whenever i have to send message to Service i have to bind it and when i go out of activity i have to unbind it which eventually destroys the service itself.
i can keep running service in background by fringing startService method but is there any way to send Messages to service without using bind as i don't want to destroy the service when i go out of activity.
LocalBroadcastManager is a great way to send messages/data,
In your service class create a private broadcastreciever and string for the intent action name:
public static String MSERVICEBROADCASTRECEIVERACTION ="whatevs";
private BroadcastReceiver mServiceBroadcastReceiver= new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Log.d("foo","onReceive called");
Log.d("foo","extra = " + intent.getStringExtra("foo")); // should print out " extra = bar"
}
};
And register it in your onCreate
#Override
public void onCreate() {
// your other code...
LocalBroadcastManager.getInstance(this).registerReceiver(mServiceBroadcastReceiver, new IntentFilter(ServiceClassName.MSERVICEBROADCASTRECEIVERACTION));
}
And De-register it in onDestroy()
#Override
public void onDestroy() {
// your other code...
LocalBroadcastManager.getInstance(this).unregisterReceiver(mServiceBroadcastReceiver);
}
As for sending messages to it, from an activity or fragment:
LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(context);
Intent intent = new Intent(ServiceClassName.MSERVICEBROADCASTRECEIVERACTION);
// add some data
intent.putExtra("foo","bar");
lbm.sendBroadcast(intent);
HTHs you send data without needing to bind!
Unbind Service will not destroy the service. it will disconnect the service connection between the activity and service
Make sure you return START_STICKY to keep your service running
#Override
public int onStartCommand(Intent intent, int flag, int startId)
{
return START_STICKY;
}
Also make sure your running the service as foreground
using notification to keep running the service after the application is removed from stack.
startForeground(1000,mBuilder.build()); // mBuilder - notification builder
I am using Service in my application and it needs to run until my application is uninstalled, but the problem is it gets killed by OS.
How can we prevent it from being killed by OS? Or if it gets killed can we restart that service again through programmatically?
You may run the service in the foreground using startForeground().
A foreground service is a service that's considered to be something
the user is actively aware of and thus not a candidate for the system
to kill when low on memory.
But bear in mind that a foreground service must provide a notification for the status bar (read here), and that the notification cannot be dismissed unless the service is either stopped or removed from the foreground.
Note: This still does not absolutely guarantee that the service won't be killed under extremely low memory conditions. It only makes it less likely to be killed.
I've been puzzled by the same issue to yours recently.but now,I've found a good solution.
First of all,you should know that, even your service was killed by OS, the onCreate method of your service would be invoked by OS in a short while.So you can do someting with the onCreate method like this:
#Override
public void onCreate() {
Log.d(LOGTAG, "NotificationService.onCreate()...");
//start this service from another class
ServiceManager.startService();
}
#Override
public void onStart(Intent intent, int startId) {
Log.d(LOGTAG, "onStart()...");
//some code of your service starting,such as establish a connection,create a TimerTask or something else
}
the content of "ServiceManager.startService()" is:
public static void startService() {
Log.i(LOGTAG, "ServiceManager.startSerivce()...");
Intent intent = new Intent(NotificationService.class.getName());
context.startService(intent);
}
However, this solution is just available for the situation of your service being killed by GC.Sometimes our service might be killed by user with Programme Manager.In this situation,your prosses will be killed,and your service will never been re-instantiated.So your service can not be restarted.
But the good news is,when the PM kill your service,it will call your onDestroy method.So we can do something with that method.
#Override
public void onDestroy() {
Intent in = new Intent();
in.setAction("YouWillNeverKillMe");
sendBroadcast(in);
Log.d(LOGTAG, "onDestroy()...");
}
The string of "YouWillNeverKillMe" is a custom action.
The most important thing of this method is,don't add any code before send the broadcast.As system will not wait for completion of onDestroy(),you must send out the broadcast as soon as posible.
Then regist a receiver in manifast.xml:
<receiver android:name=".app.ServiceDestroyReceiver" >
<intent-filter>
<action android:name="YouWillNeverKillMe" >
</action>
</intent-filter>
</receiver>
Finally,create a BroadcastReceiver,and start your service in the onReceive method:
#Override
public void onReceive(Context context, Intent intent) {
Log.d(LOGTAG, "ServeiceDestroy onReceive...");
Log.d(LOGTAG, "action:" + intent.getAction());
Log.d(LOGTAG, "ServeiceDestroy auto start service...");
ServiceManager.startService();
}
Hope this will be helpful to you,and excuse my poor written english.
Override method onStartCommand() in your service class and simply return START_STICKY (as suggested by "Its not blank"). That's all you need. If the process that runs your service gets killed (by a low memory condition for example), the Android system will restart it automatically (usually with some delay, like 5 seconds).
Don't use onStart() anymore as suggested in another answer, it's deprecated.
use
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
//**Your code **
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
ref Documentation lifecycle of Service.
Edit added method.
As far i know, onDestroy() will be called only when the service is explicitly stopped(Force Stop). But this method won't get called in case the service gets killed by OS/swiping the Recent Apps list. In those cases another event handler named onTaskRemoved(Intent) gets called. This is due to a defect in Android 4.3-4.4 as per the link here. Try using the below code:-
public void onTaskRemoved(Intent intent){
super.onTaskRemoved(intent);
Intent intent=new Intent(this,this.getClass());
startService(intent);
}
I found another solution of the problem which gurantees that your service will be always alive. In my case, this scheme resloves also the problem with FileObserver, which stops work after some period of time.
Use an activity (StartServicesActivity) to start the service (FileObserverService) as Foreground service.
Use BroadcastReceiver class (in example CommonReceiver) to restart your service in some special situations and in case it was killed.
I used this code in my app "Email Pictures Automatically"
https://play.google.com/store/apps/details?id=com.alexpap.EmailPicturesFree
Here is CommonReceiver class.
public class CommonReceiver extends BroadcastReceiver {
public void onReceive(Context paramContext, Intent paramIntent)
{
paramContext.startService(new Intent(paramContext, FileObserverService.class));
}
}
Here is its definition in AndroidManifest.xml just before application closing tag.
<receiver android:name="com.alexpap.services.CommonReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
</intent-filter>
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.USER_PRESENT"/>
</intent-filter>
</receiver>
Start service in StartServicesActivity activity.
Intent iFileObserver = new Intent(StartServicesActivity.this, FileObserverService.class);
StartServicesActivity.this.startService(iFileObserver);
Here is onStartCommand() method of the service.
public int onStartCommand(Intent intent, int flags, int startId) {
int res = super.onStartCommand(intent, flags, startId);
/*** Put your code here ***/
startServiceForeground(intent, flags, startId);
return Service.START_STICKY;
}
public int startServiceForeground(Intent intent, int flags, int startId) {
Intent notificationIntent = new Intent(this, StartServicesActivity.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);
Notification notification = new NotificationCompat.Builder(this)
.setContentTitle("File Observer Service")
.setContentIntent(pendingIntent)
.setOngoing(true)
.build();
startForeground(300, notification);
return START_STICKY;
}
I tested this code using Task Killer app, and each time the service was killed, it was restarted again almost immediately (performs onStartCommand()). It is restarted also each time you turn on the phone and after rebooting.
I use this code in my application, which emails every picture you take with your phone to predefinde list of emails. The sending email and list of receiving emails are set in another activity and are stored in Shared Preferences. I took about 100 pictures in several hours and all they were sent properly to receiving emails.
#Override
public void onDestroy() {
super.onDestroy();
startService(new Intent(this, YourService.class));
}
write above code in your service and your service will never stop even user want to destroy it or they want to kill it it will never kill untill your app not get uninstall from your device
You can try to start your service repeatedly, for example every 5 sec.
This way, when your service is running, it will perform onStartCommand() every 5 sec. I tested this scheme and it is very reliable, but unfortunately it increases slightly phone overhead.
Here is the code in your activity where you start the service.
Intent iFileObserver = new Intent(StartServicesActivity.this, FileObserverService.class);
PendingIntent pendingIntentFileObserver = PendingIntent.getService(StartServicesActivity.this, 0, iFileObserver, 0);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
Date now = new Date();
//start every 5 seconds
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, now.getTime(), 5*1000, pendingIntentFileObserver);
And here is onStartCommand() of the service.
//class variable
public static boolean isStarted = false;
public int onStartCommand(Intent intent, int flags, int startId) {
int res = super.onStartCommand(intent, flags, startId);
//check if your service is already started
if (isStarted){ //yes - do nothing
return Service.START_STICKY;
} else { //no
isStarted = true;
}
/**** the rest of your code ***/
return Service.START_STICKY;
}
First create service in another process, and write broadcaster which runs in recursion in time intervals
protected CountDownTimer rebootService = new CountDownTimer(9000, 9000) {
#Override
public void onTick(long millisUntilFinished) {
}
#Override
public void onFinish() {
sendBroadcast(reboot);
this.start();
Log.d(TAG, "rebootService sending PREVENT AUTOREBOT broadcast");
}
};
After that register broadcast receiver in main process also with timer recursion that is launched after first broadcast from service arrived
protected static class ServiceAutoRebooter extends BroadcastReceiver {
private static ServiceAutoRebooter instance = null;
private RebootTimer rebootTimer = null;
private static ServiceAutoRebooter getInstance() {
if (instance == null) {
instance = new ServiceAutoRebooter();
}
return instance;
}
public class RebootTimer extends CountDownTimer {
private Context _context;
private Intent _service;
public RebootTimer(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}
#Override
public void onTick(long millisUntilFinished) {
}
#Override
public void onFinish() {
_context.startService(_service);
this.cancel();
Log.d(TAG, "Service AutoRebooted");
}
}
#Override
public void onReceive(Context context, Intent intent) {
if (rebootTimer == null) {
Log.d(TAG, "rebootTimer == null");
rebootTimer = new RebootTimer(10000, 10000);
rebootTimer._context = context;
Intent service = new Intent(context, SomeService.class);
rebootTimer._service = service;
rebootTimer.start();
} else {
rebootTimer.cancel();
rebootTimer.start();
Log.d(TAG, "rebootTimer is restarted");
}
}
}
Service will be auto-rebooted if time at RebootTimer (main process) expires, which means that "PREVENT AUTOREBOT" broadcast from service hasn't arrived
i found a solution .... late answer but i wanted to answer...
we can send a broadcast in the ondestroy of the service and create a receiver that receives the broadcast and starts the service again.... when it is destroyed by any reasons...
pls try following:
final Messenger mMessenger = new Messenger(new IncomingHandler());
class IncomingHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
default:
super.handleMessage(msg);
}
}
}
#Override
public void onCreate() {
super.onCreate();
makeServiceForeground();
}
#Override
public IBinder onBind(Intent arg0) {
return mMessenger.getBinder();
}
private void makeServiceForeground() {
IActivityManager am = ActivityManagerNative.getDefault();
try {
am.setProcessForeground(onBind(null), android.os.Process.myPid(), true);
} catch (RemoteException e) {
Log.e("", "cant set to foreground" + e.toString());
}
}
also need add in manifest.xml
<uses-permission android:name="android.permission.SET_PROCESS_LIMIT"/>