Develop Reference

BroadcastReceiver on Android P

Since Android 9 is online and I am having a troubles to send a notification with my JobIntentService, which launched using the BroadcastReceiver .
It works great on other devices with Android <= 8.1 and I can get the notification in no time .
Sometimes It works on Android P too, but sometimes the System doesn't fire the registered services with the AlarmManager ! OR I am not able to receive it.
What is going wrong ?
AlarmReceiver.java
public class AlarmReceiver extends BroadcastReceiver {
private static final String TAG = "AlarmReceiver";
#Override
public void onReceive(Context context, Intent intent) {
if ("android.intent.action.BOOT_COMPLETED".equals(intent.getAction())) {
onBoot(context);
}
Log.d("action", "i recieved an action");
try {
Bundle bundle = intent.getExtras();
String message = bundle.getString("Push_Message", "No Content");
int type = bundle.getInt("Push_Type", -1);
Intent newIntent = new Intent(context, AppJobService.class);
newIntent.putExtra("Push_Message", message);
newIntent.putExtra("Push_Type", type);
newIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
AppJobService.enqueueWork(context, AppJobService.class, AppJobService.JOB_ID, newIntent);
} catch (Exception e) {
e.printStackTrace();
}
}
permissions in AndroidManifest.xml
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
Here I've added the Receiver to the AndroidManifest.xml
<receiver
android:name=".notifications.AlarmReceiver"
android:enabled="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
And I am registering the Service with the AlarmManager in this way inside a class, that inherits from JobIntentService
AppJobService.java
public void sendTimedNotification(String message, int type, long timeInMillis) {
Intent intent = new Intent(this, AlarmReceiver.class);
intent.putExtra("Push_Message", message);
intent.putExtra("Push_Type", type);
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(timeInMillis);
PendingIntent sender = PendingIntent.getBroadcast(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP, timeInMillis, sender);
}

As Per Document:
Alarms do not fire when the device is idle in Doze mode. Any scheduled
alarms will be deferred until the device exits Doze. If you need to
ensure that your work completes even when the device is idle there are
several options available. You can use setAndAllowWhileIdle() or
setExactAndAllowWhileIdle() to guarantee that the alarms will execute.
Another option is to use the new WorkManager API, which is built to
perform background work either once or periodically. For more
information, see Schedule tasks with WorkManager.
Take a look at https://developer.android.com/training/scheduling/alarms

BroadcastReceiver doesn't start activity when app closed

So, I've been trying to achieve that for at least five hours today and I've tried literally ANY solution found anywhere.
I'm programming a little clock app, using AlarmManager to make the app ring. It works fine when my app is open or minimized. I'm trying to make it work when the app is closed, and that's the problem. So, there is the piece of code that sets the AlarmManager :
AlarmManager am = (AlarmManager) ctxt.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(ctxt, AlarmService.class);
PendingIntent pen = PendingIntent.getBroadcast(ctxt, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
am.setExact(AlarmManager.RTC_WAKEUP, nextRing.getTime(), pen);
(Here, ctxt is the context, I've tried both getApplicationContext() and getBaseContext() and nextRing.getTime() is a long that represents the date)
Then, I have my AlarmService class (wich used to be a service, which explain the name, but is now a BroadcastReceiver and I just don't want to rename it now)
public class AlarmService extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
/*Intent cust = new Intent(context, CustomIntent.class);
context.startService(cust);*/
Bundle extras = intent.getExtras();
Intent newIntent = new Intent(context, AlarmActivity.class);
newIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
newIntent.putExtra("AlarmName", extras.getString("AlarmName"));
context.startActivity(newIntent);
}
}
So this is the try with only the BroadcastReceiver, wich doesn't work obviously, so I tried to add a IntentService (commented out code at the top) which has the following code
public class CustomIntent extends IntentService {
public CustomIntent() {
super("CustomIntent");
}
#Override
protected void onHandleIntent(Intent intent) {
Intent newIntent = new Intent(getBaseContext(), AlarmActivity.class);
newIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplication().startActivity(newIntent);
}
}
... and that's not working either ! Finally, here's the manifest I use :
<application>
[Here goes stuff that have nothing to do with my bug]
<receiver android:name=".custom_classes.AlarmService"/>
<service
android:name="com.group9.abclock.custom_classes.CustomIntent"
android:enabled="true" >
<intent-filter>
<action android:name="com.group9.abclock.custom_classes.CustomIntent" />
</intent-filter>
</service>
</application>
Sorry for the (very) long post but I tough I should explain anything I tried. Thanks in advance if you can help !

If your application is closed, you can't trigger a BroadcastReceiver because it's not registered, and you can't use Context methods because there is no Context.
If you want to execute tasks while the application is closed, you have to create another project with a Service, and start it with your application.
A Service runs in background until someone kill it, and once it's started, the main application is not needed anymore. So the ring functionality have to be implemented in this service.
Just remember that the AlarmManager.setExact, is not that exact from API 23, due to Doze Mode.

AlarmManager alarm start when system time is changed by user?

i am using AlarmManager class for setting Alarms it is working fine.
But if i set alarm like 9pm and current time is 8pm and i changed the system time to 10pm
then alarm 9pm alarm start automatically. so to solve this issue
i have searched so much but did not found any good answer
Please help
here is my code for alarm setting
final int id = (int) System.currentTimeMillis();
Intent intent = new Intent(this, AlarmReceiver.class);
intent.putExtra("requestCode", id);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, id, intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 2*60*1000, pendingIntent);

One of the options is to store all set alarms in database, then create a BroadcastReceiver which will listen for ACTION_TIME_CHANGE action. When user changes time it will be triggered. Then create a IntentService which will be responsible for resetting alarms. In this service class:
Read db and identify all passed alarms.
Cancel passed alarms
Set alarms for next day
Your code may look like as below:
In your Manifest:
<uses-permission android:name="android.permission.ACTION_TIME_CHANGE"/>
and below activities:
<receiver android:name=".TimeChangedReceiver" android:enabled="true">
<intent-filter>
<action android:name="android.intent.action.TIME_SET" />
</intent-filter>
</receiver>
<service android:name=".RestartAlarmsService"/>
Create class "TimeChangedReceiver" inside of which:
public class TimeChangedReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if("android.intent.action.TIME_SET".equals(intent.getAction())) {
Intent i = new Intent(context, RestartAlarmsService.class);
ComponentName service = context.startService(i);
}
}
}
Create "RestartAlarmsService" class inside of which:
public class RestartAlarmsService extends IntentService {
public RestartAlarmsService() {
super("RestartAlarmsService");
}
#Override
protected void onHandleIntent(Intent intent) {
// read db here
// then cancel passed alarms
// reset them to next day
}
}
You can find many tutorials on how to use Databases and implement it in your code. Hope my answer is somehow helpful.

yes it will give you broadcast, as your pending intent object is still attached to that event while you change time that is greater than you alarm firing time.
solution- validate your condition while you receive broadcast from alarm manager

Alarm is killed when OS kills app

My alarm is killed when OS kills the app. I thought that was one of the points of an Alarm, that it would keep running even though OS killed the app? I check the life of the Alarm using the "./adb shell dumpsys alarm" command, and every time OS kills my app, the Alarm is also gone. How I start my Alarm:
public static void startLocationAlarm(Context context){
if(ActivityLifecycleHandler.isApplicationInForeground()) {
return; // If App is in foreground do not start alarm!
}
String alarm = Context.ALARM_SERVICE;
AlarmManager am = ( AlarmManager ) context.getSystemService( alarm );
Intent intent = new Intent(locationBroadcastAction);
PendingIntent pi = PendingIntent.getBroadcast( context.getApplicationContext(), 0, intent, 0 );
int type = AlarmManager.ELAPSED_REALTIME_WAKEUP;
long interval = ONE_MINUTE;
long triggerTime = SystemClock.elapsedRealtime() + interval;
am.setRepeating(type, triggerTime, ONE_MINUTE, pi );
}
To add some more context, I am trying do some location operation in a service (not IntentService) in background. Here is my receiver. Used Wakeful because I did not want the service to be killed before it was done.
public class LocationBroadcastReceiver extends WakefulBroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent ) {
Intent myIntent = new Intent( context, LocationServiceAlarmOwnGoogleClient.class );
//context.startW( myIntent );
LocationBroadcastReceiver.startWakefulService(context, myIntent);
}
}
For some more information: I cancel the alarm in OnStart method of several activities that the user can return to after having it in the background. I do not know if that can cause this weird behaviour? Here is my cancel method:
public static void stopLocationAlarm(Context context){
Intent intent = new Intent(locationBroadcastAction);
PendingIntent sender = PendingIntent.getBroadcast(context.getApplicationContext(), 0, intent, 0);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(context.ALARM_SERVICE);
alarmManager.cancel(sender);
}

You can add service which listens to the phone's turning on callback.
add this permission into the manifest
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
and register reciever
<receiver android:name=".util.notification.local.MyBootCompletedService">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</receiver>
public class MyBootCompletedService extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
AlarmReceiver.startLocalNotificationService(context);
}
}

The error that caused the Alarm to be canceled had actually nothing to do with the code, but had to do with special battery settings on Huawei devices. If your app is not set as "protected" in "protected apps", the system will cancel your alarm when it kills the app. Adding your app to "protected apps" will solve this problem. Same goes for Xiaomi devices. Have to add them to "Protected apps", then the Alarm will work as intended. Thank you #CommonsWare for leading me to the solution.

Wake up app from sleep at set time

I want to send my app to sleep and then wake it up at set times. I have it going to sleep but not waking up.
This sets the wakelock:
private void setWakeLock(){
System.out.println("wakelock");
PowerManager pm = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK |
PowerManager.ACQUIRE_CAUSES_WAKEUP
| PowerManager.ON_AFTER_RELEASE, "DoNotDimScreen");
wl.acquire();
}
This sets alarms for wake/sleep times:
private void setWakeSleep(){
java.util.Calendar c = java.util.Calendar.getInstance();
c.set(java.util.Calendar.HOUR_OF_DAY, 17);
c.set(java.util.Calendar.MINUTE, 53);
c.set(java.util.Calendar.MILLISECOND, 0);
Intent sleepIntent = new Intent("SLEEP_INTENT");
PendingIntent sleepPendingIntent = PendingIntent.getBroadcast(this, 0, sleepIntent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, c.getTimeInMillis(), sleepPendingIntent);
c.set(java.util.Calendar.HOUR_OF_DAY, 18);
c.set(java.util.Calendar.MINUTE, 14);
c.set(java.util.Calendar.MILLISECOND, 0);
Intent wakeIntent = new Intent("WAKE_INTENT");
PendingIntent wakePendingIntent = PendingIntent.getBroadcast(this, 0, wakeIntent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager2 = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager2.set(AlarmManager.RTC_WAKEUP, c.getTimeInMillis(), wakePendingIntent);
}
And this is the broadcast receiver:
private BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Time updateHour = new Time();
updateHour.set(System.currentTimeMillis());
if (intent.getAction().equals("SLEEP_INTENT")) {
System.out.println("sleep");
wl.release();
}
if (intent.getAction().equals("WAKE_INTENT")) {
wl.acquire();
System.out.println("wake");
//initialise();
}
}
};
Any help greatly appreciated!

First, you don't want a wakelock; those are for keeping the device from going to sleep, which is highly anti-social unless your app really requires it (it kills the battery).
Second, your code to set the wakeup time will fail if you call it after 18:14 since you'll now be defining a time in the past. Let's ignore that for now.
Next, your intent action should be something like "org.user1797190.WAKE_INTENT" rather than simply "WAKE_INTENT" which could cause collisions. If you anticipate making this intent public, consider registering it at http://openintents.org. That's not your problem either, though.
You don't need alarmManager2 -- there's only one alarm manager in the system, so just re-use the first one.
I've never heard of making an app go to "sleep" per se. Do you mean you want the app to go away, and then come back later?
Here is what I would do. Forget about the "SLEEP_INTENT" completely. Just schedule a "WAKE_INTENT" and then call finish(). Your app will simply leave the screen.
I would forget about the broadcast receiver entirely. Instead, I would use getActivity() instead of getBroadcast() to get a pending intent that will restart the activity. Modify your manifest so that your WAKE_INTENT will go to the activity. Also, you should set the "android:launchMode" property to "singleTask" so multiple instances of your activity aren't created. You'll also need to implement onNewIntent() to handle the wakeup intent if your activity is already running when it arrives.
Finally, if your activity is part of the same application that will be creating the intent, you don't need a named intent at all; you can create them by class. You'll need another way to let the receiver know that this is a wakeup intent though.
So, putting it all together:
Your manifest should contain:
<activity android:name=".TestActivity" android:launchMode="singleTask">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
Your code should contain:
/**
* Arrange for the activity to return at a specific time.
* Call finish() after calling this method().
* This function can be called from anywhere that has a valid Context.
*/
public static void scheduleWakeup(Context ctx, long timeMillis) {
if (DEBUG) Log.d(TAG, "Scheduling wakeup for " + timeMillis);
Intent intent = new Intent(ctx, TestActivity.class);
intent.putExtra("wakeup", true);
PendingIntent pi = PendingIntent.getActivity(ctx, 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager mgr = (AlarmManager) ctx.getSystemService(Context.ALARM_SERVICE);
mgr.cancel(pi); // Cancel any previously-scheduled wakeups
mgr.set(AlarmManager.RTC_WAKEUP, timeMillis, pi);
}
...
protected void onCreate(Bundle state) {
Intent intent = getIntent();
if (intent.getBooleanExtra("wakeup", false)) {
// We were woken up by the alarm manager
}
...
}
protected void onNewIntent(Intent intent) {
if (intent.getBooleanExtra("wakeup", false)) {
// We were woken up by the alarm manager, but were already running
}
}
This is pretty close to what I'm doing in my own apps, and it works pretty well for me.
You'll have to test this yourself, of course. Log.d() is your friend.

as above. The problem was that I was using a broadcast receiver within the calling activity.