Develop Reference

Send a notification when the app is closed

How is it possible to send a notification programmatically, when the App got completely closed?
Example: The User closed the App, also in the Android Taskmanager, and waits. The App should send a notification after X Seconds or when the App check for Updates.
I tried to work with these code examples but:
Pushing notifications when app is closed - too many Activities/doesn't work
How do I get my app to send a notification when it is closed? - much information, but I don't know how to deal with it
How to send local notification android when app is closed? - much information, but I don't know how to deal with it
If you can, try to explain it at an example, because beginners (like me) can easier learn it this way.

You can use this service all you need to do is Start this service onStop() in your activity lifecycle. With this code:
startService(new Intent(this, NotificationService.class));
then you can create a new Java Class and paste this code in it:
public class NotificationService extends Service {
Timer timer;
TimerTask timerTask;
String TAG = "Timers";
int Your_X_SECS = 5;
#Override
public IBinder onBind(Intent arg0) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.e(TAG, "onStartCommand");
super.onStartCommand(intent, flags, startId);
startTimer();
return START_STICKY;
}
#Override
public void onCreate() {
Log.e(TAG, "onCreate");
}
#Override
public void onDestroy() {
Log.e(TAG, "onDestroy");
stoptimertask();
super.onDestroy();
}
//we are going to use a handler to be able to run in our TimerTask
final Handler handler = new Handler();
public void startTimer() {
//set a new Timer
timer = new Timer();
//initialize the TimerTask's job
initializeTimerTask();
//schedule the timer, after the first 5000ms the TimerTask will run every 10000ms
timer.schedule(timerTask, 5000, Your_X_SECS * 1000); //
//timer.schedule(timerTask, 5000,1000); //
}
public void stoptimertask() {
//stop the timer, if it's not already null
if (timer != null) {
timer.cancel();
timer = null;
}
}
public void initializeTimerTask() {
timerTask = new TimerTask() {
public void run() {
//use a handler to run a toast that shows the current timestamp
handler.post(new Runnable() {
public void run() {
//TODO CALL NOTIFICATION FUNC
YOURNOTIFICATIONFUNCTION();
}
});
}
};
}
}
After this you only need to combine the service with the manifest.xml:
<service
android:name=".NotificationService"
android:label="#string/app_name">
<intent-filter>
<action android:name="your.app.domain.NotificationService" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</service>

You can use alarm manager to do this [Not tested on latest Android versions and releases and is a pretty old answer].
Follow below steps :
Use alarmmanager to create an alarm of after X seconds.
Intent intent = new Intent(this, AlarmReceiver.class);
intent.putExtra("NotificationText", "some text");
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, ledgerId, intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, 'X seconds in milliseconds', pendingIntent);
Use a AlarmBroadCast receiver in your app.
Declare in manifest file :
<receiver android:name=".utils.AlarmReceiver">
<intent-filter>
<action android:name="android.media.action.DISPLAY_NOTIFICATION" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</receiver>
In the broadcast receiver's on receive, you can create the notification.
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// create notification here
}
}

You can check active apps using service and display notification if activity is not running.

Following the answer from Nikhil Gupta and referring to the website provided by Bondolin in the comments, adding the attribute android:process=":remote" to the receiver allowed me to post a notification even when the app is completely closed.
<receiver
android:name = ".utils.AlarmReceiver"
android:process=":remote" > <!-- this line is important -->
</receiver>
And the rest of the code is basically the same. An important thing to note is that the class AlarmReceiver should not contain any reference to the MainActivity, since when the app is closed, the MainActivity class is not instantiated. NullPointerException will be thrown if you attempt to reference MainActivity in the AlarmReceiver class when the app is closed.

Background process timer on android

I'm trying to get a process timer to run and keep it running in the background on android (starts with a button click).
The timer must be on 30 seconds and should even continue growing application in the background (with home button and power / screen off).
How can I do this? I tried with service and handler but not working ...
EDIT
My service tracking (process with 30 sec)
public class TrackingService extends IntentService {
private Handler mHandler;
private Runnable mRunnable;
public TrackingService() {
super("TrackingService");
}
public TrackingService(String name) {
super(name);
}
#Override
protected void onHandleIntent(Intent intent) {
long timer = 30000;
mHandler = new Handler();
mRunnable = new Runnable() {
#Override
public void run() {
//TODO - process with update timer for new 30 sec
mHandler.postDelayed(this, timer);
}
};
mHandler.postDelayed(mRunnable, timer);
}
}
My click button:
mButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//TODO - start first time and it continued every 30 seconds and continue in the background
startService(Intent intent = new Intent(this, TrackingService.class));
}
});

Ok, first of all, I really don't know if I got your question quite right.
But I think you want a timer that's being executed every 30 seconds ,if i'm not mistaken.
If so, do as following:
AlarmManager
Note: This class provides access to the system alarm services. These allow you to schedule your application to be run at some point in the future. When an alarm goes off, the Intent that had been registered for it is broadcast by the system, automatically starting the target application if it is not already running. Registered alarms are retained while the device is asleep (and can optionally wake the device up if they go off during that time), but will be cleared if it is turned off and rebooted.
Example:
in your onClick() register your timer:
int repeatTime = 30; //Repeat alarm time in seconds
AlarmManager processTimer = (AlarmManager)getSystemService(ALARM_SERVICE);
Intent intent = new Intent(this, processTimerReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
//Repeat alarm every second
processTimer.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),repeatTime*1000, pendingIntent);
And your processTimerReceiver class:
//This is called every second (depends on repeatTime)
public class processTimerReceiver extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
//Do something every 30 seconds
}
}
Don't forget to register your receiver in your Manifest.XML
<receiver android:name="processTimer" >
<intent-filter>
<action android:name="processTimerReceiver" >
</action>
</intent-filter>
</receiver>
If you ever want to cancel the alarm:
use this to do so:
//Cancel the alarm
Intent intent = new Intent(this, processTimerReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.cancel(pendingIntent);
Hope this helps you out.
PS: if this is not exactly what u want, please leave it in the comments, or if someone wants to edit this, please do so.

Oh god, don't ever use AlarmManager for 30s timers. It's kind of an overkill and also put a significant drain on device resources (battery, CPU...).
Perhaps you could try using a real background Service instead of IntentService as IntentService tends to shut itself down when it runs out of work. Not sure if this is the case here, but it's worth a try.

The process of the service is killed after the application is removed from the application tray

I am starting a service (or re-starting the running service) when an activity is launched, using :
Intent intent = new Intent(this, MyService.class);
startService(intent);
Later on based on certain actions, the same activity binds to the service using
bindService(new Intent(this, MyService.class), mConnection, Context.BIND_AUTO_CREATE);
And when the activity is destroyed, I call
unbindService(mConnection);
Earlier, the service used to restart when I killed the same activity/application from the application tray and showed the "message 1 process 1 service running" under running apps.
Now, the service does not restart on killing the same activity/application.
And I get the message "0 process 1 service running", which means the service is actually not running.
The service does not restart on application being closed. My application consists of one activity. Also the service is successfully started when launched after a system boot.
Why does the process of the service gets killed when I start it using startService() ??
edit
The service used to re-start earlier after i closed the app from the application tray. But now suddenly with the SAME code, it doesn't. It happens with other apps too when i close them. eg.

Here is a workaround I came across and works well for re-starting a service if its process is killed on closing the application. In your service, add the following code.
I came across this workaround in this thread.
#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);
}
Seems to be a bug that the process of the application is killed. There is no point for a service to run if its process is killed.

Please be aware of that: onDestroy is not always called. You should not put code that way.
When activity forced closed or closed by system abnormally, onDestroy is not getting called.

Unfortunately, this is a complicated problem due to the way Android works. There are a number of strategies that each work around different parts of the problem. For best results, combine multiple strategies together.
Note that some of these strategies may no longer be necessary in more recent Android versions.
1. Start an activity
What to do
Taken from Foreground service killed when receiving broadcast after acitivty swiped away in task list:
In the foreground service:
#Override
public void onTaskRemoved( Intent rootIntent ) {
Intent intent = new Intent( this, DummyActivity.class );
intent.addFlags( Intent.FLAG_ACTIVITY_NEW_TASK );
startActivity( intent );
}
In the manifest:
<activity
android:name=".DummyActivity"
android:theme="#android:style/Theme.NoDisplay"
android:enabled="true"
android:allowTaskReparenting="true"
android:noHistory="true"
android:excludeFromRecents="true"
android:alwaysRetainTaskState="false"
android:stateNotNeeded="true"
android:clearTaskOnLaunch="true"
android:finishOnTaskLaunch="true"
/>
(If your service is in a different process then set this activity's process to the same one.)
In DummyActivity.java:
public class DummyActivity extends Activity {
#Override
public void onCreate( Bundle icicle ) {
super.onCreate( icicle );
finish();
}
}
Side effects
Causes the recents activity to close. Normally, swiping away an app doesn't close the recents activity.
Disadvantages
This only takes effect when the dummy activity starts, which may take half a second or more, so this still leaves the service open to being killed for a bit.
Explanation
When you remove/swipe your app away, a flag called waitingToKill is set. While this flag is set, Android may kill the process at any point in the future, such as when you receive a broadcast. Starting an activity clears this flag.
2. Spam a BroadcastReceiver with foreground broadcasts
What to do
Merge this into your service code:
if (Build.VERSION.SDK_INT >= 16) {
Intent intent = new Intent(this, DummyReceiver.class);
intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND);
//This seems to be timing-related; the more times we do this,
//the less likely the process gets killed
for (int i = 0; i < 50; ++i)
sendBroadcast(intent);
}
Create a dummy broadcast receiver:
public class DummyReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {}
}
Add the receiver to your manifest:
<receiver android:name=".DummyReceiver" />
Side effects
May cause a slight (~250ms) delay/hang when the task is removed from the recents screen.
Disadvantages
This only keeps the process alive while it is receiving the broadcasts. the waitingToKill flag is still set, so the process may still be killed afterwards, such as when a broadcast is received.
Explanation
If your process isn't running in foreground priority, Android will try to kill it immediately. Receiving foreground broadcasts temporarily prevents this, resulting in the waitingToKill flag being set instead.
3. Don't bind to services
Binding to a service seems to increase the likelihood of the service's process being killed immediately when a task is removed.

I know this question is old but I recently encountered this problem and suddenly my service get stopped on closing app. Earlier it was working fine. This problem wasted my lot of time. To others who have similar problem make sure that YOUR BACKGROUND DATA RESTRICTION IS OFF.
This was the problem I had and it actually makes sense as when background data is Restricted background process won't run.

onDestroy is not always called. The Main problem in your case is ur unable to start the service when app closed,that time android OS(In Some OS) will kill the service, If you are not able to restart the service then call a alarm manger to start the reciver like this,
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");
}
}

when there is no binding to a service or well established foreground then android system recognize the service as unused overloading service that should be shut down. Here is the best way to maintain your service even if the app is closed: AlarmManager or Service

Android Service Stops When App Is Closed

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.

Alarm Manager Reliability

I've been struggling with this problem for days. I've also checked the documentation and several topics but didn't find any solution / explanation.
I am testing my application on LG p500 but I did a few test on Droid too and I get the same result.
My application uses AlarmHandler to schedule alarm. The application works correctly on the emulator and also on the device until the device has enough free memory.
When I start several other applications on the device and the memory is low the alarm will not fire anymore. As soon as I stop the "other" application the alarm works fine again.
Let me report the test and the result.
I set an alarm on my application 10 minute later.
I start several application (browser, google map, gmail, K9Mail,....)
I start the catlog to see the log of my application
Wait 15 minute without working on the phone
After 10 minutes the alarm should be fired but nothing happen until I wakeup my phone pressing a button
When I wake-up my phone the alarm immediatly fires and all the notificatin happen.
I stop the "other" application I previously started (browser, google map,...)
Set again an alarm 10 minute later
I start the catlog to see the log of my application
Wait without working on the phone
10 minutes later the alarm fires and I get notified.
I did this test several time and I get the same result.
Then I tried to set an alarm using the "Catch" application I previously downloaded from the market and I get the same behaviour so it looks like this is not a problem of my application.
Looking at the log of my application I do not see any error / exception but it looks like that when the system is low on memory something happen and the broadcast receiver does not start until the phone is waked up throught the keyboard. As soon as I wake-up the phone the receiver start and all the notification happen.
Here the code I used:
The Receiver:
public class NotificationReceiver extends BroadcastReceiver
{
public static final String LOG_TAG = "YAAS - Notification Receiver";
#Override
public void onReceive(Context context, Intent intent)
{
ScheduleActivityService.acquireStaticLock(context);
Log.i(LOG_TAG, "Received alarm - id: " + intent.getIntExtra("id", -1));
Intent intent2 = new Intent(context, ScheduleActivityService.class);
intent2.putExtra("id", intent.getIntExtra("id", -1));
context.startService(intent2);
}
}
The Service
public class ScheduleActivityService extends Service
{
public static final String LOCK_NAME_STATIC="it.hp.yaas.AppService.Static";
public static final String LOG_TAG = "YAAS - ActivityService";
private static PowerManager.WakeLock lockStatic = null;
private final IBinder mBinder = new LocalBinder();
public class LocalBinder extends Binder
{
public ScheduleActivityService getService()
{
return ScheduleActivityService.this;
}
}
#Override
public IBinder onBind(Intent intent)
{
return mBinder;
}
public static void acquireStaticLock(Context context) {
getLock(context).acquire();
}
synchronized private static PowerManager.WakeLock getLock(Context context)
{
if (lockStatic == null)
{
PowerManager mgr = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
lockStatic = mgr.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, LOCK_NAME_STATIC);
lockStatic.setReferenceCounted(true);
}
return(lockStatic);
}
/**
* This method is called when an alarm fires that is its alarm time is reached.
* The system assume that the alarm fired match the alarm time of the first
* activity.
* #param intent intent fired
* #param flag
* #param startId
*/
#Override
public int onStartCommand(Intent intent, int flag, int startId)
{
super.onStartCommand(intent, flag, startId);
try {
Log.i(LOG_TAG, "Alarm fired: " + startId + " - id: " + intent.getIntExtra("id", -1));
AlarmHandler.getInstance().onAlarmFired(intent.getIntExtra("id", -1));
}
finally { getLock(this).release(); }
return START_STICKY;
}
#Override
public void onDestroy()
{
super.onDestroy();
Log.i(LOG_TAG, "Destroy");
}
}
An piece of code from AlarmHandler, the routine called to schedule the alarm:
public synchronized void onAlarmFired(int alarmId)
{
scheduledAlarmId = -1;
Alarm alarmFired = pop();
if (alarmFired == null) return;
Log.i(LOG_TAG, "onAlarmFired (Alarm: " + alarmFired + ") at (time: " + Utilities.convertDate(new Date(), "HH:mm:ss") + ")");
notifyAlarmListener(alarmFired);
if (alarmFired.reschedule(null) != null) add(alarmFired);
Alarm alarm = peek();
if (alarm != null && scheduledAlarmId != alarm.getId()) scheduleEvent(alarm);
}
/**
* Schedule an alarm through AlarmManager that trigger next activity notification
* #param alarm alarm to be scheduled
*/
private void scheduleEvent(Alarm alarm)
{
Log.i(LOG_TAG, "scheduleEvent - (Alarm: " + alarm + ")");
Intent intent = new Intent(context, NotificationReceiver.class);
intent.putExtra("id", alarm.getId());
// In reality, you would want to have a static variable for the request code instead of 192837
PendingIntent sender = PendingIntent.getBroadcast(context, 192837, intent, PendingIntent.FLAG_UPDATE_CURRENT);
// Get the AlarmManager service
AlarmManager am = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP, alarm.getTime().getTime(), sender);
scheduledAlarmId = alarm.getId();
}
And finally this is a piece of Manifest file:
<activity android:name=".ListActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".EditActivity"/>
<activity android:name=".SettingsActivity"/>
<service android:name="ScheduleActivityService"
android:label="YAAS Service"/>
<receiver android:name="NotificationReceiver" />

Are you sure your process doesn't get killed when you start all those applications? If it does, the alarms you set will die with it. It's not exactly clear who and when schedules the alarm in your code, but if it's the service, since it's sticky, it will eventually gets re-started, and you will get an alarm at some point (when you wake the device).
An easy way to check what alarms are registered at different points of your testing:
# adb shell dumpsys alarm

My code is very similar to yours on an alarm app that I wrote and use regularly. I haven't been able to reproduce the problem that you describe. I can't seem to get my phone to a state of extremely low memory. I opened every app I have installed and still have 260M free on my HTC Rezound.
As a safeguard in my app I used alarmmanager.setRepeating() instead of .set(). I set the repeat interval to 20 seconds. I passed the alarm ID as an intent extra just as you have. When my service starts it immediately cancels the pending intent using the alarm ID. My logic here is that if for any reason my alarm fails it will continue to try every 20 seconds until it succeeds.

In your code is AlarmManager.set(), which is not guaranteed to fire at the time you specify. It may fire 30 minutes or even 6 hours later, which I've seen happen on devices like the Xiaomi POCO F1.
Instead use AlarmManager.setExact() to schedule your code to run at a specific time.
Android 12 introduces an exact alarms permisison. If you don't want to deal with that, you can instead use AlarmManager.setWindow() with a small window like 15 minutes.