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AlarmManager fires alarms at wrong time
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Closed 7 years ago.
I have four Repeating Alarms in my app each of which fires at different timings to do some important tasks.
They are
Alarm 1 - 12:30 AM
Alarm 2 - 01:00 AM
Alarm 3 - 06:00 AM
Alarm 4 - 12:15 PM
Every alarm fires no problems. Time interval for each alarms are 24 hrs. But each of the firing at random timings.
Alarm Set Time Actual Firing Time
Alarm 1 12:30 AM 06:31 AM
Alarm 2 01:00 AM 06:01 AM
Alarm 3 06:00 AM 06:01 AM
Alarm 4 12:15 PM Still not fired 4 hours after that time
My Code was
Alarm 1
Intent myIntent=new Intent(MainPage.this,db_restore.class);
PendingIntent pi=PendingIntent.getBroadcast(MainPage.this,1,myIntent,0);
AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DATE, 1);
calendar.set(Calendar.HOUR_OF_DAY, 12);
calendar.set(Calendar.MINUTE, 30);
calendar.set(Calendar.SECOND,0);
calendar.set(Calendar.AM_PM,Calendar.AM);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),1000*60*60*24,pi);
Alarm 2
Intent mor_flag=new Intent(MainPage.this,MorningFlag.class);
PendingIntent mor_intent=PendingIntent.getBroadcast(MainPage.this,3,mor_flag,0);
AlarmManager mor_alarm=(AlarmManager)getSystemService(Context.ALARM_SERVICE);
Calendar calendar=Calendar.getInstance();
calendar.add(Calendar.DATE, 1);
calendar.set(Calendar.HOUR_OF_DAY, 1);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND,0);
calendar.set(Calendar.AM_PM,Calendar.AM);
mor_alarm.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),1000*60*60*24,mor_intent);
Alarm 3
Intent late_start1=new Intent(MainPage.this,late_start.class);
PendingIntent piLate=PendingIntent.getBroadcast(MainPage.this,2,late_start1,0);
AlarmManager alarmManager=(AlarmManager)getSystemService(Context.ALARM_SERVICE);
Calendar calendar=Calendar.getInstance();
calendar.add(Calendar.DATE, 1);
calendar.set(Calendar.HOUR_OF_DAY, 6);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND,0);
calendar.set(Calendar.AM_PM,Calendar.AM);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 1000*60*60*24, piLate);
Toast.makeText(MainPage.this,"Alarm Service started for Late Start monitoring",Toast.LENGTH_LONG).show();
Alarm 4
Intent eve_flag=new Intent(MainPage.this,EveningFlag.class);
PendingIntent eve_intent=PendingIntent.getBroadcast(MainPage.this,4,eve_flag,0);
AlarmManager eve_alarm=(AlarmManager)getSystemService(Context.ALARM_SERVICE);
Calendar calendar=Calendar.getInstance();
calendar.add(Calendar.DATE, 1);
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, 12);
calendar.set(Calendar.MINUTE, 15);
calendar.set(Calendar.SECOND,0);
calendar.set(Calendar.AM_PM, Calendar.PM);
eve_alarm.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),1000*60*60*24,eve_intent);
I don't know what I'm doing wrong. Please take a look and help me. Thanks.
Note: I'm checking this in API Level 19 Android 4.4.4 with minimum as 14.
From the API
DOCS(https://developer.android.com/training/scheduling/alarms.html)
As of Android 4.4 (API Level 19), all repeating alarms are inexact. This means Android synchronizes repeating alarms from multiple apps and fires them at the same time.
So if you want an exact alarm use Alarm Manager's
setExact (int type, long triggerAtMillis, PendingIntent operation)
method.
If you want repeating alarms with exact timing then you would have to write a logic where you will set an alarm (Not a repeating alarm) and when this alarm goes off set another alarm for next interval.
Try using AlarmManager.setExact() and give some rep to this post
For api levels below 19 you should use AlarmManager.setRepeating() and your alarms will trigger exactly at specified time. Thou on api levels 19 and above this will no longer work. There was change in android so that all repeating alarms are inexact. So if you would like to achieve exact repeating alarm you should schedule alarm with AlarmManager.setExact() and then when alarm triggers do it again for next week and so on every week.
Related
I'm using an alarm manager like this :
// Set the alarm to start at 8:30 a.m.
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, 8);
calendar.set(Calendar.MINUTE, 30);
alarmMgr.setInexactRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
AlarmManager.INTERVAL_DAY, alarmIntent);
So my alarm runs at 8:30 every day, but let's suppose that the user's phone is off at 8:30, how can I make it so the alarm starts running whenever the user's phone is available and the hour is within an interval. Let's say the interval is [8h, 18h] so once the user's phone is on and the current time is within that interval the alarm should be triggered.
Also, how is it possible to stop the alarm at 18h (supposing that it started running before)
I'm currently making a native Android app and I have code working to schedule a notification to appear on the device using the AlarmManager class:
Intent intent = new Intent(this, NotifyActivity.class);
AlarmManager alarmMgr = (AlarmManager)getSystemService(Activity.ALARM_SERVICE);
PendingIntent alarmIntent = PendingIntent.getService(this, 0, intent, 0);
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 9);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
alarmMgr.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 24*60*60*1000, alarmIntent);
Two things:
The notification goes off every time the app is opened. I don't want this to happen.
The notifications is suppose to be going off at 9am device time (or so I'm led to believe). This is not happening and it looks like it goes off every 9 hours or so.
Can anyone tell me why the notification goes off every time the app is opened and why the notification is not only being triggered when the device reaches 9am?
Thanks
From the doc of AlarmManager:
If the stated trigger time is in the past, the alarm will be
triggered immediately
You are setting your alarm to 9:00 , if you launch after this hour, trigger time is in the past, so the alarm is going off when the app is opened.
You can check if the current time is after alarm, if so, you add one day to the alarm and it will going off the next day. For example:
Calendar cal = Calendar.getInstance();
Calendar cal_now = Calendar.getInstance();
cal.setTimeInMillis(System.currentTimeMillis());
cal.set(Calendar.HOUR_OF_DAY, 9);
cal.set(Calendar.MINUTE, 0);
if (cal.before(cal_now)) {//if its in the past
cal.add(Calendar.DATE, 1);
}
alarmMgr.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), 24*60*60*1000, alarmIntent);
Hope it helps,
I'm new to android and using alarmManager and I was wondering if there is a way to set an alarm in android that triggers for example every monday until a certain specific date. Like this :
Start date 10/09/15
Remind me something every monday at 2:30 pm
Until
End date 11/09/15
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 14);
calendar.set(Calendar.MINUTE, 30);
int weekInMillis = 7 * 24 * 60 * 60 * 1000;
alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
weekInMillis, PendingIntent.getBroadcast(context, 0, new Intent(context, ReminderAlarmWakefulBroadcastReceiver.class), PendingIntent.FLAG_UPDATE_CURRENT));
Above code snippet sets an alarm for 2:30 PM that repeats itself every week. Tweak calendar for varying the time at which the alarm goes off. For example, the coming Monday.
When the alarm goes off, it sends a broadcast which will be received by ReminderWakefulBroadcastReceiver, a custom receiver containing the code that you want to run every Monday at 2:30 PM. This code should also check whether it is time to cancel the alarm and if it is, the following code cancels it:
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.cancel(PendingIntent.getBroadcast(context, 0, new Intent(context, ReminderAlarmWakefulBroadcastReceiver.class));
References:
AlarmManager, Scheduling Repeating Alarms, PendingIntent
If you know how to setup an Alarm, the solution is quite simple:
1) At the time you setup the Alarm, calculate the maximum timestamp you want it to run, and save it as a local preference.
2) Then in the Alarm code itself, each time it is triggered you can make a first test to see if the current timestamp is before or after your limit preference saved at first time.
3) If reached, then cancel the Alarm as #karthik said. If not, keep your code going...
I need to the Android app to send notification to remind users at 8am, 3pm and 8pm every day. So I use the following three lines in onCreate() of the MainActivity, when the application starts. However, when I run the app, all three notification are coming at once instead of at the wanted time.
setRepeatedNotification(1,8,0,0);
setRepeatedNotification(2,15,0,0);
setRepeatedNotification(3,20,0,0);
Why is that? I also attach the setRepeatedNotification function here. Thank you!
private void setRepeatedNotification(int ID, int hh, int mm, int ss) {
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
Intent alarmIntent = new Intent(MainActivity.this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(MainActivity.this, ID, alarmIntent, 0);
Calendar calendar = Calendar.getInstance();
// calendar.set();
calendar.set(Calendar.HOUR_OF_DAY, hh);
calendar.set(Calendar.MINUTE, mm);
calendar.set(Calendar.SECOND, ss);
// Clear previous everyday pending intent if exists.
if (null != mEverydayPendingIntent) {
alarmManager.cancel(mEverydayPendingIntent);
}
mEverydayPendingIntent = pendingIntent;
alarmManager.setRepeating(AlarmManager.RTC, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, mEverydayPendingIntent);
}
Here is the updated code:
private void setRepeatedNotification(int ID, int hh, int mm, int ss) {
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
Intent alarmIntent = new Intent(StartActivity.this, AlarmReceiver.class);
alarmIntent.putExtra("ID",ID);
Log.d("setRepeatedNotification", "ID:" + ID);
PendingIntent pendingIntent = PendingIntent.getBroadcast(StartActivity.this, ID, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);
Calendar calendar = Calendar.getInstance();
Calendar now = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, hh);
calendar.set(Calendar.MINUTE, mm);
calendar.set(Calendar.SECOND, ss);
//check whether the time is earlier than current time. If so, set it to tomorrow. Otherwise, all alarms for earlier time will fire
if(calendar.before(now)){
calendar.add(Calendar.DATE, 1);
}
mEverydayPendingIntent = pendingIntent;
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, mEverydayPendingIntent);
}
I see two potential problems with your setup with AlarmManager. The first arises when the device goes to sleep.
From AlarmManager's documentation:
If an alarm is delayed (by system sleep, for example, for non _WAKEUP alarm types), a skipped repeat will be delivered as soon as possible. After that, future alarms will be delivered according to the original schedule; they do not drift over time. For example, if you have set a recurring alarm for the top of every hour but the phone was asleep from 7:45 until 8:45, an alarm will be sent as soon as the phone awakens, then the next alarm will be sent at 9:00.
As you can see, if you've set an alarm and the device has gone to sleep, without using AlarmManager.RTC_WAKEUP there could be a long delay depending on how long the device has been in sleep for. If you've never touched your device and no other alarms caused a wakeup, it could cause all your alarms to stack up upon the next hour that the device is awake for.
Another potential issue I see is that you are retrieving a Calendar instance representing the time right now, but then setting the hour, minute and second by yourself. The current day and the current year have been automatically populated from the current time.
Again, from the documentation (emphasis mine):
If the stated trigger time is in the past, the alarm will be triggered immediately, with an alarm count depending on how far in the past the trigger time is relative to the repeat interval.
In this case, if your method was invoked past 8 pm on the given day, calendar.getTimeInMillis() will return a timestamp in the past for all three alarms, causing them to be triggered immediately since 8 am, 3 pm and 8 pm have already past in that day. In this case, you must first evaluate whether the current time is past the alarm interval you are trying to set and add 1 day more onto the time you are setting to make sure the alarm has been set in the future.
I wanted to know How I can set Alarm for a particular time. For example I want to set alarm for
morning 9am daily. I googled a lot but found only the way to set alarm for a given interval only. like after 2 hours or next day.
hope this code helps you
Calendar calendar = Calendar.getInstance();
//9 AM
calendar.set(Calendar.HOUR_OF_DAY, 9);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
PendingIntent pi = PendingIntent.getService(context, 0, new Intent(context, YourClass.class), PendingIntent.FLAG_UPDATE_CURRENT);
am.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pi);
you should create BroadcastReceiver to receive intent.
read the documentation for further details
I googled a lot but found only the way to set alarm for a given interval only. like after 2 hours or next day.
The second parameter to setRepeating() on AlarmManager is when you want the alarm to go off first. Set that to be 9am tomorrow using a Calendar object, and use an RTC or RTC_WAKEUP alarm.