Develop Reference

dynamic alarm manager at midnight

my mean goal is to run a task periodically at midnight (00:00:00)
but the user can set the period based on the interval (daily, weekly , monthly)
let's assume that this job is a backup Scheduling.
this task will triggred at midnight but based on the user preference (midnight everyday, every week , or monthly ), and if the phone was in the doze mode or even off , wait untill the next start and start backup.
when i start implementing the code , i started with JobService and JobScheduler , but unfortunately i learned that i can set the repetitive but i can't set the exact time, so the last solution was to work with alarmmanager.
i use this code for triggering the alarm :
public static void setTheTimeToStartBackup(Context context,String periode) {
int DATA_FETCHER_RC = 123;
AlarmManager mAlarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
Intent intent = new Intent(context, BackUpAlarmRecevier.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, DATA_FETCHER_RC,intent, PendingIntent.FLAG_UPDATE_CURRENT);
long interval = 0;
switch (periode){
case "never":
return;
case "daily":
alarmStartTime.set(Calendar.HOUR_OF_DAY, 0);
interval = AlarmManager.INTERVAL_DAY;
break;
case "weekly":
alarmStartTime.set(Calendar.DAY_OF_WEEK, 1);
interval = AlarmManager.INTERVAL_DAY*7;
break;
case "monthly":
alarmStartTime.set(Calendar.WEEK_OF_MONTH, 1);
interval = AlarmManager.INTERVAL_DAY*30;
break;
}
alarmStartTime.set(Calendar.HOUR_OF_DAY, 0);
alarmStartTime.set(Calendar.MINUTE, 0);
alarmStartTime.set(Calendar.SECOND, 0);
mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),interval, pendingIntent);
Log.e("Alarm","Set for midnight");
}
this is my receiver :
public class BackUpAlarmRecevier extends BroadcastReceiver {
SharedPreferences preferences;
#Override
public void onReceive(Context context, Intent intent) {
Log.e("BackUpAlarmReciver","Triggred");
PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "TAG:APP");
wl.acquire();
sendNotification(context);// simple notification...
Toast.makeText(context, "Alarm !!", Toast.LENGTH_LONG).show();
startBackupProcess();
wl.release();
}}
the problem is task never start.
so i went to test it with less time interval (15min as the minimum possible as i read ), so i change my first function setTheTimeToStartBackup to this :
public static void setTheTimeToStartBackup(Context context,String periode) {
int DATA_FETCHER_RC = 123;
AlarmManager mAlarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.SECOND, 55);
Intent intent = new Intent(context, BackUpAlarmRecevier.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, DATA_FETCHER_RC,intent, PendingIntent.FLAG_UPDATE_CURRENT);
mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),AlarmManager.INTERVAL_FIFTEEN_MINUTES, pendingIntent);
Log.e("Alarm","Set for midnight");
}
and exactly the same problem , nothing started, no log , no notification , nothing.
and i already set the Receiver in my manifest with all permission like that :
<receiver android:name=".job.BackUpAlarmRecevier"
android:enabled="true"
android:process=":remote"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
what im doing wrong in both cases ? and if it work , this code will persist for ever or i need to set it again each time ?
thanks :)
EDIT:
i call my function setTheTimeToStartBackup in the MainActivity.

You could set it to occur at midnight if you did the appropriate time calculations. Dynamically get the current time and date, calculate when to register the broadcast for the alarm manager. Customize the onReceive method to set another alarm at 12pm again.
Either way you can trigger a broadcast receiver by registering your receiver manually.
Broadcast receiver class:
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
System.out.println("Alarm received!! ");
// Register alarm again here.
}
}
Code to register a receiver with a custom intent filter.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AlarmManager mAlarmManager = (AlarmManager)getApplicationContext().getSystemService(Context.ALARM_SERVICE);
getApplicationContext().registerReceiver(new AlarmReceiver(), new IntentFilter("AlarmAction"));
PendingIntent broadcast = PendingIntent.getBroadcast(this, 0, new Intent("AlarmAction"), 0);
// Add dynamic time calculations. For testing just +100 milli.
mAlarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 100, broadcast);
;
}
You could achieve what you wanted through a background service.

My suggestion would be to turn the problem around a bit.
Create three topics on Firebase (daily, weekly, monthly). Subscribe users to appropriate topics. Have a Firebase function that is triggered by CRON job which sends the data notification down to the device, this data notification should schedule one-time WorkManager job for the update. This way you can control everything from server-side, if the phone is off, it will still execute as soon as it turns on and you don't need to manually take care of catching the Boot completed with alarm manager etc.

Hovering toast every 5 minutes

I've seen several examples on how to make some event to be repeated even when the app isnt running, but still I'm not sure if I got it.
With AlarmManager you can make your app to wake up to do something in some fixed interval without it consuming system resources between the periods, right?
But can it be to show up a toast over your current activity instead of having an Activity with a layout for it?

AlarmReceiver class:
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// this is where to start activity or service to launch toast message
}
}
In activity or boot receiver:
private static final int PERIOD = 60000; //or whatever you need for repeating alarm
AlarmManager mgr = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Intent alIntent = new Intent(context, AlarmReceiver.class);
PendingIntent pi = PendingIntent.getBroadcast(context, 0, alIntent, 0);
mgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 60000, PERIOD, pi);
In AndroidManifest, add:
<receiver android:name=".AlarmReceiver"></receiver>

Android IntentService only executes once

I am using Android AlarmManger to schedule an IntentService to run after small intervals.
Here is my AlarmManger:
static void setNextSchedule(Context ctx, long interval){
AlarmManager manager = (AlarmManager) ctx.getSystemService(Context.ALARM_SERVICE);
Intent nIntent = new Intent(ctx, DService.class);
PendingIntent pIntent = PendingIntent.getActivity(ctx, 1, nIntent, PendingIntent.FLAG_UPDATE_CURRENT);
manager.setRepeating(AlarmManager.ELAPSED_REALTIME,
SystemClock.elapsedRealtime() + interval, interval, pIntent);
Log.i(ScheduleAlarm.class.getSimpleName(), "Next alarm set");
}
And my IntentService:
#Override
protected void onHandleIntent(Intent intent) {
Log.i(DService.class.getSimpleName(), "Service starting");
ScheduleAlarm.setNextSchedule(getApplicationContext(), 15000);
}
Currently it just holds code for testing. Now this code will run successfully with no problems once the app starts but after 15 seconds it will state that the service is starting in the logcat but the code won't execute.
How to get the intenet service the execute the code inside the onHandleIntent each time it runs?
Thanks

When using a PendingIntent, the factory method needs to match the type of component that your Intent is for:
If your Intent points to an activity, use getActivity()
If your Intent points to a service, use getService()
If your Intent points to a BroadcastReceiver, use getBroadcast()
If your Intent points to none of the above, go directly to jail, do not pass Go!, do not collect $200 :-)

AlarmManager only lets one Service through when used with setRepeating in Android

I've been struggling with this for a couple of days. What I want to do is run a service periodically, about 2-3 minutes apart. I have an Activity that is responsible for the interface and setting up the first alarm.
The alarm is configured by a BroadcastReceiver which looks like this:
public class Receiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
String message = "Alarm worked";
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
setAlarm(context);
}
public void setAlarm(Context context){
AlarmManager am = (AlarmManager) context.
getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, Receiver.class);
PendingIntent pi = PendingIntent.getBroadcast(context,
0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
Intent dailyUpdater = new Intent(context, DiscoveryService.class);
context.startService(dailyUpdater);
am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
+ (1000 * 30) , pi);
}
}
I've tried using setRepeating for AlarmManager, but it still has the same effect. What happens is that the AlarmManager works how it should, it fires an Intent which the receiver gets and executes onReceive periodically, as it should. However, it executes the service only the first time. After the first time, the alarms still go off, but the service is not executed.
I read some threads from people with similar problems, and one of them mentioned that PendingIntent lasts for only one send. Thus, I opted out to setting the alarm every time so I can set pendingIntent flag for updating every time.
I tried making my service an intentService, which is fine, but then my bluetooth scanner inside the service does not work because intentService thread terminates without waiting for my bluetooth discovery to finish.
Anyone have any idea what can help me?
Here is part of my service:
public class DiscoveryService extends Service {
public void onCreate() {
super.onCreate();
Toast.makeText(this, "MyAlarmService.onCreate()",
Toast.LENGTH_LONG).show();
findEverything();
}
}
EDIT: This is the code that I currently have.
public void onReceive(Context context, Intent intent) {
String message = "Alarm worked";
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
Intent dailyUpdater = new Intent(context, DiscoveryService.class);
context.startService(dailyUpdater);
}
public void setAlarm(Context context){
// get a Calendar object with current time
AlarmManager am=(AlarmManager)context.
getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, Receiver.class);
PendingIntent pi = PendingIntent.getBroadcast(context, 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),
(1000 * 30) , pi);
}

What happens is that the AlarmManager works how it should, it fires an Intent which the reciever gets and executes onReceive periodically, as it should. However, it executes the service only the first time. After the first time, the alarms still go off, but the service is not executed.
You are calling startService() once when you are scheduling the alarm. You are not calling startService() at all from your BroadcastReceiver. Yet you are scheduling the alarm via the BroadcastReceiver. Hence, when the alarm goes off, the service will not be sent a command, because you are not sending it a command.
I read some threads from people with similar problems, and one of them mentioned that PendingIntent lasts for only one send.
That is only if you use FLAG_ONE_SHOT.
Anyone have any idea what can help me?
Call startService() from your onReceive() method, instead of from your setAlarm() method. Also, add in all the WakeLock management logic, since you are using a _WAKEUP alarm and you are not able to use my WakefulIntentService.

AlarmManager Not called next day if the app sleeps for abt 1 day

I am developing an android app which shows a notification every 12 hour if the time is saved in the database. So everytime a data is entered or edited in the database ,I cancel the current alarmmanager and start a fresh new one so that I dont miss one. Also on reboot I have called the alarmmanager. On the broadcast receiver, the database is checked for entry and if found a notification is set and the app is opened automatically.
So when I test the app by changing the date manually,the app works as expected.Also on reboot the app works.But if I keep the app idle for nearly 14 hours,the notification is not set ,but if I open the app and suspend it the notification is set after that.
This is how I call the alarmmanager.
Intent alarmintent = new Intent(context, package.Alarm_Manager.class);
alarmintent.putExtra("note","Notify");
sender = PendingIntent.getBroadcast(context , 0 , alarmintent , PendingIntent.FLAG_CANCEL_CURRENT | Intent.FILL_IN_DATA);
alarm_manger = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
alarm_manger.cancel(sender);
Calendar cal = Calendar.getInstance();
long now = cal.getTimeInMillis();
alarmintent = new Intent(context, package.Alarm_Manager.class);
alarmintent.putExtra("note","Notification");
sender = PendingIntent.getBroadcast(context , 0 , alarmintent , PendingIntent.FLAG_CANCEL_CURRENT | Intent.FILL_IN_DATA);
alarm_manger = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarm_manger.setRepeating(AlarmManager.RTC_WAKEUP, now, AlarmManager.INTERVAL_HALF_DAY, sender);
This is the broadcast receiver
#Override
public void onReceive(Context context, Intent intent)
{
NotificationManager manger = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
Calendar cal = Calendar.getInstance();
date = (int)(cal.getTimeInMillis()/1000);
Notification notification = new Notification(R.drawable.vlcsnap_396460 , "Notify" , System.currentTimeMillis());
PendingIntent contentIntent = PendingIntent.getActivity(context, 0, intent, 0);
notification.setLatestEventInfo(context, "App", "Notify" , contentIntent);
notification.flags = Notification.FLAG_INSISTENT;
manger.notify( 0 , notification);
}

You don't need to call alarm_manager.cancel(sender); if you set the PendingIntent.FLAG_CANCEL_CURRENT.
Your call to
alarm_manger.setRepeating(AlarmManager.RTC_WAKEUP, now, AlarmManager.INTERVAL_HALF_DAY, sender);
will trigger the alarm right away, since the now is already passed when you set the alarm.
I suggest you use
now + DateUtils.HOUR_IN_MILLIS / 2
for the triggerAtMillis parameter
Did you tried to schedule it for smaller interval? Does it get triggered ?

After having seen your Alarm_Manager code, I think it is illegal to do this in your BroadcastReceiver object directly. Quote:
If this BroadcastReceiver was launched through a tag, then the object is no longer alive after returning from this function.
I believe there is no other way than to create a Service which is informed by your BroadcastReceiver, and make sure that the Service calls setLatestEventInfo() with itself (this) as the Context.
The reason why your asynchronous Broadcast fails while it works when your app is running is probably that the Context provided to the BroadcastReceiver lives only for the duration of the call to the BroadcastReceiver when your app does not run. So the Notification service, which only runs after your BroadcastReceiver has died along with the temporary context, is missing a valid context.
When your app runs, the Broadcast probably comes with your Activity or Application object as Context, and this is still vaild when the Notification manager runs.
Hope this helps.
Update: An `IntentService`` will do. You don't want a full time Service for that.
Update 2: Some snippets.
<service android:name=".MyIntentService" android:label="#string/my_intent_service_name" />
public final class MyIntentService extends IntentService {
public MyIntentService() {
super("service name");
// set any properties you need
}
#Override
public void onCreate() {
super.onCreate();
// do init, e.g. get reference to notification service
}
#Override
protected void onHandleIntent(Intent intent) {
// handle the intent
// ...especially:
notification.setLatestEventInfo(this, "App", "Notify" , contentIntent);
// ...
}
}
public final class MyAlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
context.startService(new Intent(context, MyIntentService.class));
}
}