Start AlarmManager if device is rebooted

Question

In my app I want to run some code every day at a specific time using an AlarmManager. In the android documentation I found this:

Registered alarms are retained while the device is asleep [...] but will be cleared if it is turned off and rebooted.

And that is the problem. I want to run the code even if the user reboots the phone. If the user reboots the phone he currently has to relaunch my app to start alarms again. How can I prevent this? Is there a better mechanism I should use instead?

Answer 1

Create Boot Receiver using following code :

public class BootBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context pContext, Intent intent) {
        // Do your work related to alarm manager
    }
}

In your Manifest, register this Broadcast receiver :

<receiver
android:name="com.yourapp.BootBroadcastReceiver"
android:enabled="true" >
<intent-filter>
    <action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>

And don't forget to add permission in AndroidManifest.xml :

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

Answer 2

Use can u create service using broadcast reciever on device boot up

 <receiver android:enabled="true" android:name=".YourReceiver"
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</receiver>

Permission:

 <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

Answer 3

You will need to add a boot receiver in your manifest like this

<application ...  >

    <receiver android:name=".OnBootReceiver" >
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
            <uses-permission android:name="android.permission.WAKE_LOCK" />
        </intent-filter>
    </receiver>
</application>

And then create the boot receiver class like this...

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class OnBootReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context ctxt, Intent intent) {
AlarmHelper.setAlarm(ctxt);
}
}

My alarm helper class is a simple start of day alarm like this...

public class AlarmHelper {

public static void testAlarm(Context context) {
Calendar when = Calendar.getInstance();
when.add(Calendar.SECOND, 10);
setAlarm(context, when);    
}

public static void setAlarm(Context context) {
Calendar when = Calendar.getInstance();
when.add(Calendar.DAY_OF_YEAR, 1);
when.set(Calendar.HOUR_OF_DAY, 0);
when.set(Calendar.MINUTE, 0);
when.set(Calendar.SECOND, 0);
setAlarm(context, when);
}

    @SuppressLint("SimpleDateFormat")
private static void setAlarm(Context context, Calendar when) {

SharedPreferences prefs = PreferenceManager
.getDefaultSharedPreferences(context.getApplicationContext());

Boolean showNotifications = prefs.getBoolean("PREF_SHOW_NOTIFICATIONS",
false);

if (showNotifications) {    
AlarmManager am = (AlarmManager) context
.getSystemService(Context.ALARM_SERVICE);

am.setRepeating(AlarmManager.RTC_WAKEUP, when.getTimeInMillis(), AlarmManager.INTERVAL_DAY, getPendingIntent(context.getApplicationContext()));

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

Log.i(TAG, "Alarm set " + sdf.format(when.getTime()));
}
}