Develop Reference

How to really update a widget precisely every minute

I'm stumped. I know this question has already been answered a hundred times but nothing I've tried works.
My question: I made an Android widget that needs to refresh precisely at each minute, much like all clock widgets do. (This widget tells me in how many minutes are left before my train leaves, a one minute error makes it useless).
Here are my attempts to far, and the respective outcomes:
I put android:updatePeriodMillis="60000" in my appwidget_info.xml. However, as specified in API Docs, "Updates requested with updatePeriodMillis will not be delivered more than once every 30 minutes" and indeed that's about how often my widget gets updated.
I tried using an AlarmManager. In my WidgetProvider.onEnabled:
AlarmManager am = (AlarmManager)context.getSystemService
(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
long now = System.currentTimeMillis();
// start at the next minute
calendar.setTimeInMillis(now + 60000 - (now % 60000));
am.setRepeating(AlarmManager.RTC, calendar.getTimeInMillis(), 60000,
createUpdateIntent(context));
however as stated in the API docs, "as of API 19, all repeating alarms are inexact" and indeed my widget actually gets updated every five minutes or so.
Based on the previous point I tried setting targetSdkVersion to 18 and saw no difference (updates every five minutes or so).
The setRepeating documentation seems to recommend using setExact. I tried the following. At the end of my update logic:
Calendar calendar = Calendar.getInstance();
long now = System.currentTimeMillis();
long delta = 60000 - (now % 60000);
Log.d(LOG_TAG, "Scheduling another update in "+ (delta/1000) +" seconds");
calendar.setTimeInMillis(now + delta);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setExact(AlarmManager.RTC, calendar.getTimeInMillis(), //UPDATE_PERIOD_SECONDS * 1000,
createUpdateIntent(context));
It works perfectly for a couple minutes and then reverts to updating every five minutes or so (and not even near minute changes). Here are some timestamps of when the update intent is received:
21:44:17.962
21:52:37.232
21:59:13.872
22:00:00.012 ← hey suddenly it becomes exact again??
22:01:47.352
22:02:25.132
22:06:56.202
Some recommend using a Handler. I defined a Service which I start when the widget provider is enabled, and does this after update code:
int delay = (int)(60000 - (System.currentTimeMillis() % 60000));
Log.d(LOG_TAG, "Scheduling another update in " + delay/1000 + " seconds");
new Handler().postDelayed(new Runnable() {
public void run() {
Log.d(LOG_TAG, "Scheduled update running");
updateAppWidget();
}
}, delay);
and this one works perfectly for several hours, but then the service gets suddenly killed and gets "scheduled to restart after HUGE delay". Concretely, the widget just gets stuck at some point and doesn't get updated at all.
Some other options I've seen online: the linked post above suggests creating a foreground service (which, if I understand correctly, means having a permanently visible icon in my already crowded status bar. I don't have one permanent icon for each clock widget I use so that should not be necessary). Another suggestion is to run a high priority thread from the service, which feels awfully overkill.
I've also seen recommendations to use Timers and BroadcastReceivers but the former is said to be "not appropriate for the task" and I remember having trouble doing the latter. I think I had to do it in a service and then the service gets killed just like when I use Handlers.
It should be noted that the AlarmManager seems to work well when the phone is connected to the computer (presumably because it means the battery is charging), which doesn't help because most of the time I want to know when my train will leave is when I'm already on the way...
As the Handler is perfectly accurate but just stops working after a while, and the AlarmManager option is too inaccurate but does not stop working, I'm thinking of combining them by having AlarmManager start a service every ten minutes or so, and have that service use a Handler to update the display each minute. Somehow I feel this will get detected by Android as a power hog and get killed, and anyway I'm sure I must be missing something obvious. It shouldn't be that hard to do what's essentially a text-only clock widget.
EDIT: if it matters, I'm using my widget on a Samsung Galaxy Note 4 (2016-06-01) with Android 6.0.1.

Sorry, i totally forgot, was busy.. Well, i hope you got the idea of what you need, snippets are following, hope i dod not forgot something.
on the widget provider class.
public static final String ACTION_TICK = "CLOCK_TICK";
public static final String SETTINGS_CHANGED = "SETTINGS_CHANGED";
public static final String JOB_TICK = "JOB_CLOCK_TICK";
#Override
public void onReceive(Context context, Intent intent){
super.onReceive(context, intent);
preferences = PreferenceManager.getDefaultSharedPreferences(context);
AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
ComponentName thisAppWidget = new ComponentName(context.getPackageName(), WidgetProvider.class.getName());
int[] appWidgetIds = appWidgetManager.getAppWidgetIds(thisAppWidget);
if (intent.getAction().equals(SETTINGS_CHANGED)) {
onUpdate(context, appWidgetManager, appWidgetIds);
if (appWidgetIds.length > 0) {
restartAll(context);
}
}
if (intent.getAction().equals(JOB_TICK) || intent.getAction().equals(ACTION_TICK) ||
intent.getAction().equals(AppWidgetManager.ACTION_APPWIDGET_UPDATE)
|| intent.getAction().equals(Intent.ACTION_DATE_CHANGED)
|| intent.getAction().equals(Intent.ACTION_TIME_CHANGED)
|| intent.getAction().equals(Intent.ACTION_TIMEZONE_CHANGED)) {
restartAll(context);
onUpdate(context, appWidgetManager, appWidgetIds);
}
}
private void restartAll(Context context){
Intent serviceBG = new Intent(context.getApplicationContext(), WidgetBackgroundService.class);
context.getApplicationContext().startService(serviceBG);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
scheduleJob(context);
} else {
AppWidgetAlarm appWidgetAlarm = new AppWidgetAlarm(context.getApplicationContext());
appWidgetAlarm.startAlarm();
}
}
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
private void scheduleJob(Context context) {
ComponentName serviceComponent = new ComponentName(context.getPackageName(), RepeatingJob.class.getName());
JobInfo.Builder builder = new JobInfo.Builder(0, serviceComponent);
builder.setPersisted(true);
builder.setPeriodic(600000);
JobScheduler jobScheduler = (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE);
int jobResult = jobScheduler.schedule(builder.build());
if (jobResult == JobScheduler.RESULT_SUCCESS){
}
}
#Override
public void onEnabled(Context context){
restartAll(context);
}
#Override
public void onDisabled(Context context){
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
JobScheduler jobScheduler = (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE);
jobScheduler.cancelAll();
} else {
// stop alarm
AppWidgetAlarm appWidgetAlarm = new AppWidgetAlarm(context.getApplicationContext());
appWidgetAlarm.stopAlarm();
}
Intent serviceBG = new Intent(context.getApplicationContext(), WidgetBackgroundService.class);
serviceBG.putExtra("SHUTDOWN", true);
context.getApplicationContext().startService(serviceBG);
context.getApplicationContext().stopService(serviceBG);
}
WidgetBackgroundService
public class WidgetBackgroundService extends Service {
private static final String TAG = "WidgetBackground";
private static BroadcastReceiver mMinuteTickReceiver;
#Override
public IBinder onBind(Intent arg0){
return null;
}
#Override
public void onCreate(){
super.onCreate();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
if(intent != null) {
if (intent.hasExtra("SHUTDOWN")) {
if (intent.getBooleanExtra("SHUTDOWN", false)) {
if(mMinuteTickReceiver!=null) {
unregisterReceiver(mMinuteTickReceiver);
mMinuteTickReceiver = null;
}
stopSelf();
return START_NOT_STICKY;
}
}
}
if(mMinuteTickReceiver==null) {
registerOnTickReceiver();
}
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
#Override
public void onDestroy(){
if(mMinuteTickReceiver!=null) {
unregisterReceiver(mMinuteTickReceiver);
mMinuteTickReceiver = null;
}
super.onDestroy();
}
private void registerOnTickReceiver() {
mMinuteTickReceiver = new BroadcastReceiver(){
#Override
public void onReceive(Context context, Intent intent){
Intent timeTick=new Intent(WidgetProvider.ACTION_TICK);
sendBroadcast(timeTick);
}
};
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_TIME_TICK);
filter.addAction(Intent.ACTION_SCREEN_ON);
registerReceiver(mMinuteTickReceiver, filter);
}
}
RepeatingJob class
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
public class RepeatingJob extends JobService {
private final static String TAG = "RepeatingJob";
#Override
public boolean onStartJob(JobParameters params) {
Log.d(TAG, "onStartJob");
Intent intent=new Intent(WidgetProvider.JOB_TICK);
sendBroadcast(intent);
return false;
}
#Override
public boolean onStopJob(JobParameters params) {
return false;
}
}
AppWidgetAlarm class
public class AppWidgetAlarm {
private static final String TAG = "AppWidgetAlarm";
private final int ALARM_ID = 0;
private static final int INTERVAL_MILLIS = 240000;
private Context mContext;
public AppWidgetAlarm(Context context){
mContext = context;
}
public void startAlarm() {
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.MILLISECOND, INTERVAL_MILLIS);
AlarmManager alarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
Intent alarmIntent = new Intent(WidgetProvider.ACTION_TICK);
PendingIntent removedIntent = PendingIntent.getBroadcast(mContext, ALARM_ID, alarmIntent, PendingIntent.FLAG_CANCEL_CURRENT);
PendingIntent pendingIntent = PendingIntent.getBroadcast(mContext, ALARM_ID, alarmIntent, PendingIntent.FLAG_CANCEL_CURRENT);
Log.d(TAG, "StartAlarm");
alarmManager.cancel(removedIntent);
// needs RTC_WAKEUP to wake the device
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), INTERVAL_MILLIS, pendingIntent);
}
public void stopAlarm()
{
Log.d(TAG, "StopAlarm");
Intent alarmIntent = new Intent(WidgetProvider.ACTION_TICK);
PendingIntent pendingIntent = PendingIntent.getBroadcast(mContext, ALARM_ID, alarmIntent, PendingIntent.FLAG_CANCEL_CURRENT);
AlarmManager alarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
alarmManager.cancel(pendingIntent);
}
}
manifest
<receiver android:name=".services.SlowWidgetProvider" >
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
</intent-filter>
<intent-filter>
<action android:name="CLOCK_TICK" />
</intent-filter>
<intent-filter>
<action android:name="JOB_CLOCK_TICK" />
</intent-filter>
<intent-filter>
<action android:name="SETTINGS_CHANGED" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.TIME_SET" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.TIMEZONE_CHANGED" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.DATE_CHANGED" />
</intent-filter>
<intent-filter>
<action android:name="android.os.action.DEVICE_IDLE_MODE_CHANGED"/>
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.ACTION_DREAMING_STOPPED" />
</intent-filter>
<meta-data android:name="android.appwidget.provider"
android:resource="#xml/slow_widget_info" />
</receiver>
<service
android:name=".services.RepeatingJob"
android:permission="android.permission.BIND_JOB_SERVICE"
android:exported="true"/>
<service android:name=".services.WidgetBackgroundService" />

The code snippets provided by #Nikiforos was a blessing for me, although I've felt into many problems when using them on Android 8, thus I decided to let you know how I've solved my issues. There are two problems related with the snippets provided:
they use BackgroundService which is now forbidden in some cases in Android 8
they use implicit broadcasts which have also been restricted in Android O (you can read about why it happened here)
To address first issue I had to switch from BackgroundService to ForegroundService. I know this is not possible in many cases, but for those who can do the change here are the instructions to modify the codes:
Change the restartAll() function as follows:
private void restartAll(Context context){
Intent serviceBG = new Intent(context.getApplicationContext(), WidgetBackgroundService.class);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
// for Android 8 start the service in foreground
context.startForegroundService(serviceBG);
} else {
context.startService(serviceBG);
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
scheduleJob(context);
} else {
AppWidgetAlarm appWidgetAlarm = new AppWidgetAlarm(context.getApplicationContext());
appWidgetAlarm.startAlarm();
}
}
Update the onStartCommand() function in your WidgetBackgroundService code:
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// for Android 8 bring the service to foreground
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
startForeground(1, buildForegroundNotification("Test 3"));
if(intent != null) {
if (intent.hasExtra("SHUTDOWN")) {
if (intent.getBooleanExtra("SHUTDOWN", false)) {
if(mMinuteTickReceiver!=null) {
unregisterReceiver(mMinuteTickReceiver);
mMinuteTickReceiver = null;
}
stopSelf();
return START_NOT_STICKY;
}
}
}
if(mMinuteTickReceiver==null) {
registerOnTickReceiver();
}
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
Add sendImplicitBroadcast() function to your WidgetBackgroundService:
private static void sendImplicitBroadcast(Context ctxt, Intent i) {
PackageManager pm=ctxt.getPackageManager();
List<ResolveInfo> matches=pm.queryBroadcastReceivers(i, 0);
for (ResolveInfo resolveInfo : matches) {
Intent explicit=new Intent(i);
ComponentName cn=
new ComponentName(resolveInfo.activityInfo.applicationInfo.packageName,
resolveInfo.activityInfo.name);
explicit.setComponent(cn);
ctxt.sendBroadcast(explicit);
}
}
Modify registerOnTickReceiver() function in the following way:
private void registerOnTickReceiver() {
mMinuteTickReceiver = new BroadcastReceiver(){
#Override
public void onReceive(Context context, Intent intent){
Intent timeTick=new Intent(LifeTimerClockWidget.ACTION_TICK);
// for Android 8 send an explicit broadcast
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
sendImplicitBroadcast(context, timeTick);
else
sendBroadcast(timeTick);
}
};
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_TIME_TICK);
filter.addAction(Intent.ACTION_SCREEN_ON);
registerReceiver(mMinuteTickReceiver, filter);
}
Hope it helps!

Use the widget itself as the host for the delayed runnable. Widgets have a postDelayed method.
If the widget is killed and recreated, then also recreate the runnable as part of the basic initialization.
Edit:
The above suggestion was based on the inaccurate assumption that the OP was writing a custom view, not an app widget. For an app widget my best suggestion is:
create a foreground service with ONE icon.
the service manages all widgets and clicking on the notification icon will show the various reminders that are active and/allow them to be managed

There is no correct and fully working answer to widget update every minute. Android OS developer purposely exclude such feature or api in order to save the battery and workload.
For my case, I tried to create clock homescreen appwidget and tried many attempt on alarm manager, service etc.
None of them are working correctly.
For those who want to create Clock Widget, which need update time everyminute precisely.
Just use
<TextClock
android:id="#+id/clock"
style="#style/widget_big_thin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|top"
android:ellipsize="none"
android:format12Hour="#string/lock_screen_12_hour_format"
android:format24Hour="#string/lock_screen_24_hour_format"
android:includeFontPadding="false"
android:singleLine="true"
android:textColor="#color/white" />
for digital clock text view and
For Analog Clock
<AnalogClock xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/analog_appwidget"
android:dial="#drawable/appwidget_clock_dial"
android:hand_hour="#drawable/appwidget_clock_hour"
android:hand_minute="#drawable/appwidget_clock_minute"
android:layout_width="match_parent"
android:layout_height="match_parent" />
I've found those code from Google Desk Clock Opensource Project. You may already know Google Clock has such widget which update precisely every minute.
To learn more
Google Desk Clock Opensource Repo

Try this code
Intent intent = new Intent(ACTION_AUTO_UPDATE_WIDGET);
PendingIntent alarmIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.MINUTE, calendar.get(Calendar.MINUTE) + 1);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
AlarmManager alarmMgr = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmMgr.setInexactRepeating(AlarmManager.RTC, calendar.getTimeInMillis(), 60 * 1000, alarmIntent);

AlarmManager getting killed with the app

I created an app to send message using alarm manager but if i put an alarm for a long duration the app is killed by android automatically, so i need to prevent the app from getting killed.Please tell me how can I do it.
Calendar cal = Calendar.getInstance();
int currentApiVersion = android.os.Build.VERSION.SDK_INT;
if (currentApiVersion > android.os.Build.VERSION_CODES.LOLLIPOP_MR1) {
cal.set(Calendar.MINUTE, time_picker.getMinute());
cal.set(Calendar.HOUR_OF_DAY, time_picker.getHour());
} else {
//Setting the date and time from the time picker
cal.set(Calendar.MINUTE, time_picker.getCurrentMinute());
cal.set(Calendar.HOUR_OF_DAY, time_picker.getCurrentHour());
}
//System clock time
Calendar c = Calendar.getInstance();
Long a ;//=(long) (Calendar.getInstance().get(Calendar.SECOND) * 1000);
if(cal.get(Calendar.HOUR_OF_DAY) < c.get(Calendar.HOUR_OF_DAY))
h = (cal.get(Calendar.HOUR_OF_DAY) + 24 - c.get(Calendar.HOUR_OF_DAY)) * 60;
else
h = (cal.get(Calendar.HOUR_OF_DAY) - c.get(Calendar.HOUR_OF_DAY * 60;
m = (cal.get(Calendar.MINUTE) - c.get(Calendar.MINUTE));
a = (m + h) * 60;
myIntent = new Intent(this, MyReceiver.class);
myIntent.putExtra("pos", array.select);
//Pending Intent for sending the intent afterwards
pendingIntent[array.select] = PendingIntent.getBroadcast(this.getApplicationContext(), array.select, myIntent, 0);
alarmManager[array.select] = (AlarmManager) (this.getSystemService(Context.ALARM_SERVICE));
alarmManager[array.select].set(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime() + a * 1000, pendingIntent[array.select]);
pendingarray.add(pendingIntent[array.select]);
sms_list.Phone[array.select] = Phone;
Intent back = new Intent(this, sms_list.class);
back.putExtra("PHONE", Phone);
back.putExtra("Flag",2);
back.putExtra("MSG", Message);
back.putExtra("HOUR", (int) cal.get(Calendar.HOUR_OF_DAY));
back.putExtra("MIN", (int) cal.get(Calendar.MINUTE));
back.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(back);
If the answer is wake lock can you please tell me where to use it.

You can use a service to do it, this will also work after the device is rebooted. You also have to make the service foreground to prevent the system from killing it. It can be done by adding an ongoing notification. See the service code below.
In your Manifest add the following
<receiver
android:name=".Autostart"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<action android:name="android.intent.action.QUICKBOOT_POWERON" />
</intent-filter>
</receiver>
<service
android:name=".StarterService"
android:enabled="true"
android:exported="true" />
Then create a new class as follows:
public class Autostart extends BroadcastReceiver {
/**
* Listens for Android's BOOT_COMPLETED broadcast and then executes
* the onReceive() method.
*/
#Override
public void onReceive(Context context, Intent arg1) {
Log.d("Autostart", "BOOT_COMPLETED broadcast received. Executing starter service.");
Intent intent = new Intent(context, StarterService.class);
context.startService(intent);
}
}
And finally your service as follows:
public class StarterService extends Service {
private static final String TAG = "MyService";
/**
* starts the AlarmManager.
*/
#Override
public void onCreate() {
super.onCreate();
//TODO: Start ongoing notification here to make service foreground
}
#Override
public void onStart(Intent intent, int startid) {
//TODO: Put your AlarmManager code here
//TODO: you also need to add some logic to check if some previous work is pending in case of a device reboot
Log.d(TAG, "onStart");
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
//TODO: cancel the notification
Log.d(TAG, "onDestroy");
}
}
Now all you need to do is call the service whenever you need to send the message.
PS: I know an answer is accepted but hope this helps you or someone else.

An alarm should be triggered in a Broadcast Receiver.
If it performs long-lived operations, you should then use threads or Services. Both of them can be launched from a receiver.
EDIT
As a short example, I use this method in a button's onClickListener in the activity :
scheduleAlarm(name);
Method :
public void scheduleAlarm(String client)
{
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
String delay = sharedPref.getString(SettingsActivity.PREF_DELIVERY_DELAY, "48");
// time at which alarm will be scheduled here alarm is scheduled at 1 day from current time,
// we fetch the current time in milliseconds and added 1 day time
// i.e. 24*60*60*1000= 86,400,000 milliseconds in a day
Long time = new GregorianCalendar().getTimeInMillis()+ Integer.parseInt(delay) * 1000; //todo change seconds to hours
// create an Intent and set the class which will execute when Alarm triggers, here we have
// given AlarmReciever in the Intent, the onRecieve() method of this class will execute when
// alarm triggers and
//we will write the code to send SMS inside onRecieve() method pf Alarmreciever class
Intent intentAlarm = new Intent(this, AlarmReceiver.class);
intentAlarm.putExtra("CLIENT", client);
// create the object
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
//set the alarm for particular time
//todo string res
alarmManager.set(AlarmManager.RTC_WAKEUP,time, PendingIntent.getBroadcast(this,1, intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
Toast.makeText(this, "Alarm Scheduled in " + delay + " hours", Toast.LENGTH_LONG).show();
}
And finally, the AlarmReceiver.java
package com.patrickmiller.test2;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.support.v4.app.NotificationCompat;
import android.widget.Toast;
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent)
{
Toast.makeText(context, "Alarm received", Toast.LENGTH_SHORT).show();
String client = intent.getStringExtra("CLIENT");
Notify(context, client);
}
public void Notify(Context context, String client) {
//todo expanded layout with options Fiche de contact | Rapport and cover image
//todo send name, address, phone, email and id through Intent to ContactClientActivity
//todo delete notification when generated
try {
NotificationCompat.Builder mBuilder =
new NotificationCompat.Builder(context)
//todo set notification icon, content title and content text as string resources
.setSmallIcon(R.drawable.warning)
.setContentTitle(client)
.setContentText("N'oubliez pas de générer le rapport du client");
Intent resultIntent = new Intent(context, ContactClientActivity.class);
//todo may need to expend instead of calling activity. Buttons will do.
// Because clicking the notification opens a new ("special") activity, there's
// no need to create an artificial back stack.
PendingIntent resultPendingIntent =
PendingIntent.getActivity(
context,
0,
resultIntent,
PendingIntent.FLAG_UPDATE_CURRENT
);
mBuilder.setContentIntent(resultPendingIntent);
// Sets an ID for the notification
int mNotificationId = 001;
// Gets an instance of the NotificationManager service
NotificationManager mNotifyMgr = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);
// Builds the notification and issues it.
mNotifyMgr.notify(mNotificationId, mBuilder.build());
}
catch(Exception e) {
Toast.makeText(context, String.valueOf(e), Toast.LENGTH_LONG).show();
}
}
}
You don't have to care about the client's thing. Just the way I scheduled the alarm..
My operation is a short-lived one, which is sending a notification. If you plan a long-lived operation, you should start a service or a thread from the receiver (onReceive callback method).

ok, your app is finished because is running in the main thread, so you need to make this process in other thread that is not killed when the app is closed. check this documentation from the official page. if you decide start using asyncTask class check this reference

Android - Trouble with service sending multiple local notifications

I've inherited a code base for an Android app and I'm facing a particularly though problem with local notifications.
The idea is to send a notification for each event which is scheduled in the future, considering also the reminder preference on how many minutes before the event the user wants to be notified.
Everything works just fine, except that after the notification is thrown for the first time, if the user opens the app before the event starts, the notification gets thrown another time. This happens every time the app is opened between (event start date - reminder) and event start date.
I've already gave a look at this and also this with no luck.
I've read that using a service may cause exactly this problem and some suggest to remove it but I think this is needed since the notification must be thrown also when the app is closed.
Currently the structure of the code is the following:
Edit - updated description of TabBarActivity
Inside TabBarActivity I have the method scheduleTravelNotification that schedules the AlarmManager.
This method is executed everytime there is a new event to be added on local database, or if an existing event have been updated.
The TabBarActivity runs this method inside the onCreate and onResume methods.
TabBarActivity is also the target of the notification - onclick event.
private static void scheduleTravelNotification(Context context, RouteItem routeItem) {
long currentTime = System.currentTimeMillis();
int alarmTimeBefore = routeItem.getAlarmTimeBefore();
long alarmTime = routeItem.getStartTime() - (alarmTimeBefore * 1000 * 60);
if(alarmTimeBefore < 0){
return;
}
if(alarmTime < currentTime){
return;
}
Intent actionOnClickIntent = new Intent(context, TravelNotificationReceiver.class);
PendingIntent travelServiceIntent = PendingIntent.getBroadcast(context, System.currentTimeMillis(), actionOnClickIntent, PendingIntent.FLAG_ONE_SHOT);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(alarmTime);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), travelServiceIntent);
Log.e("NEXT ALARM", "Time: " + String.valueOf(calendar.getTimeInMillis()));
}
This is TravelNotificationReceiver.java (should I use LocalBroadcastReceiver instead of BroadcastReceiver?)
public class TravelNotificationReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Log.e("RECEIVER", "received TravelNotification request");
Intent notificationIntent = new Intent(context, TravelNotificationService.class);
context.startService(notificationIntent);
}
}
TravelNotificationService.java extends NotificationService.java setting as type = "Travel", flags = 0, title = "something" and text = "something else".
public abstract class NotificationService extends Service {
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
super.onCreate();
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
sendNotification();
return super.onStartCommand(intent, flags, startId);
}
public abstract String setNotificationType();
public abstract int setNotificationFlags();
public abstract String setNotificationTitle();
public abstract String setNotificationText();
/**
* Executes all the logic to init the service, prepare and send the notification
*/
private void sendNotification() {
int flags = setNotificationFlags();
String type = setNotificationType();
NotificationHelper.logger(type, "Received request");
// Setup notification manager, intent and pending intent
NotificationManager manager = (NotificationManager) this.getApplicationContext().getSystemService(this.getApplicationContext().NOTIFICATION_SERVICE);
Intent intentAction = new Intent(this.getApplicationContext(), TabBarActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this.getApplicationContext(), 0, intentAction, flags);
// Prepares notification
String title = setNotificationTitle();
String text = setNotificationText();
Notification notification = NotificationHelper.buildNotification(getApplicationContext(), title, text, pendingIntent);
// Effectively send the notification
manager.notify(101, notification);
NotificationHelper.logger(type, "Notified");
}
}
Edit - Here's the code for NotificationHelper.buildNotification
public static Notification buildNotification(Context context, String title, String text, PendingIntent pendingIntent) {
NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
builder.setAutoCancel(true);
builder.setContentText(text);
builder.setContentTitle(title);
builder.setContentIntent(pendingIntent);
builder.setSmallIcon(R.mipmap.launcher);
builder.setCategory(Notification.CATEGORY_MESSAGE);
builder.setVisibility(Notification.VISIBILITY_PUBLIC);
return builder.build();
}
Thank you for the answers!
Edit I've seen also this but has no accepted answers, while this post suggest something that I think it's already managed with if(alarmTime < currentTime){ return; } in scheduleTravelNotification.

This may not be your exact problem, but at a glance, you're sending the notification in onStartCommand() which can itself be run many times during the lifetime of the service -- for example, if you issue the service start command "blindly" in an onCreate of an activity, it will happen every time the activity is (re)created.
You have a few options for handling this.
One is to create a boolean flag as a property of the service, default to false, and check it before sending the notification. If it's false, send the notification and set it to true, and if it's already true you do not send a notification.
Another is to check and see if the service is already running, and if it is, don't send the service start command in the first place. This can be tedious to do everywhere, and violates DRY, so if you take this route you may want to create a static method in your service class which checks to see if the service is running and then starts it if not, and call that instead of explicitly starting the service.

Similar to user3137702 answer you could simple have a static boolean of APPISINFORGROUND which is checked everytime the send notification method is hit, and managed from your application/activities code.
As User said it is likely that your onStartCommand method is being called at odd times due to the app / service lifecycle.
Alternatively check your receiver is not being called somewhere else from your code.

It may be your NotificationHelper class which is causing an issue. Please share the code for this class.
One thought may be that your notification is not set to be auto cancelled, check if you include the setAutoCancel() method in your Notification Builder.
Notification notification = new Notification.Builder(this).setAutoCancel(true).build();

I've found a way to make it work, I'm posting this since it seems to be a problem of many people using the approach suggested in this and this articles. After months of testing I can say I'm pretty satisfied with the solution I've found.
The key is to avoid usage of Services and rely on AlarmScheduler and Receivers.
1) Register the receiver in your manifest by adding this line:
<receiver android:name="<your path to>.AlarmReceiver" />
2) In your activity or logic at some point you want to schedule a notification related to an object
private void scheduleNotification(MyObject myObject) {
// Cal object to fix notification time
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(myObject.getTime());
// Build intent and extras: pass id in case you need extra details in notification text
// AlarmReceiver.class will receive the pending intent at specified time and handle in proper way
Intent intent = new Intent(this, AlarmReceiver.class);
intent.putExtra("OBJECT_ID", myObject.getId());
// Schedule alarm
// Get alarmManager system service
AlarmManager alarmManager = (AlarmManager) getApplicationContext().getSystemService(getBaseContext().ALARM_SERVICE);
// Build pending intent (will trigger the alarm) passing the object id (must be int), and use PendingIntent.FLAG_UPDATE_CURRENT to replace existing intents with same id
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), myObject.getId(), intent, PendingIntent.FLAG_UPDATE_CURRENT);
// Finally schedule the alarm
alarmManager.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), pendingIntent);
}
3) Define AlarmReceiver
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// Find object details by using objectId form intent extras (I use Realm but it can be your SQL db)
MyObject myObject = RealmManager.MyObjectDealer.getObjectById(intent.getStringExtra("OBJECT_ID"), context);
// Prepare notification title and text
String title = myObject.getSubject();
String text = myObject.getFullContent();
// Prepare notification intent
// HomeActivity is the class that will be opened when user clicks on notification
Intent intentAction = new Intent(context, HomeActivity.class);
// Same procedure for pendingNotification as in method of step2
PendingIntent pendingNotificationIntent = PendingIntent.getActivity(context, myObject.getId(), intentAction, PendingIntent.FLAG_UPDATE_CURRENT);
// Send notification (I have a static method in NotificationHelper)
NotificationHelper.createAndSendNotification(context, title, text, pendingNotificationIntent);
}
}
4) Define NotificationHelper
public class NotificationHelper {
public static void createAndSendNotification(Context context, String title, String text, PendingIntent pendingNotificationIntent) {
// Get notification system service
NotificationManager notificationManager = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);
// Build notification defining each property like sound, icon and so on
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context);
notificationBuilder.setContentTitle(title);
notificationBuilder.setContentText(text);
notificationBuilder.setSmallIcon(R.drawable.ic_done);
notificationBuilder.setCategory(Notification.CATEGORY_MESSAGE);
notificationBuilder.setVisibility(Notification.VISIBILITY_PUBLIC);
notificationBuilder.setAutoCancel(true);
notificationBuilder.setContentIntent(pendingNotificationIntent);
notificationBuilder.setDefaults(Notification.DEFAULT_SOUND);
notificationManager.notify(1001, notificationBuilder.build());
}
}
At this point it should work and schedule / trigger notification at the right time, and when notification is opened it will appear only once starting the activity declared in notification pending intent.
There is still a problem, AlarmManager have a "volatile" storage on user device, so if user reboots or switch off the phone you will lose all intents that you previously scheduled.
But fortunately there is also a solution for that:
5) Add at top of your manifest this uses permission
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
6) Right below the line added at step 1 register the boot receiver
<receiver android:name="<your path to>.BootReceiver" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
7) Define the BootReceiver
public class BootReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// Do something very similar to AlarmReceiver but this time (at least in my case) since you have no source of intents loop through collection of items to understand if you need to schedule an alarm or not
// The code is pretty similar to step 3 but repeated in a loop
}
}
At this point your app should be able to schedule / trigger notification and restores those reminders even if the phone is switched off or rebooted.
Hope this solution will help someone!

Not sure of what to choose between Service, BroadcastReceiver and AlarmManager

Hello guys i am building an app in which i would like to add subscription. That means that every user has to pay monthly.
So i want to check if the user has paid he will be able to proceed with the orders if he didn't then i want a dialog to redirect him to pay. What would you suggest me to use Service, BroadcastReceiver or AlarmaManager?
I was thinking of creating a Service and within it create an AsyncTask that will check to the database if the user has paid and then if not inform the user with a dialog. Also i was thinking of creating Notiofications to the user that the subscription ending.
What is your opinion???

I developed a similar function to check many bills. I combined the three methods to ensure stability. But I think you should use Google Play In-app Billing to achieve subscriptions instead of using a local database. If you must use a database to subscribe:
1.After users subscribe, saved info to the database and start a service. the service start a thread,the thread get Data and Analyzing user payments. then use AlarmManager to set Notification and stopSelf.
public class NotificationService extends Service {
...
private AlarmManager am;
private PendingIntent pi;
private NotificationManager mNM;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Thread thread = new Thread(null, mTask, "AlarmService_Service");
thr.start();
return START_REDELIVER_INTENT;
}
Runnable mTask = new Runnable() {
public void run() {
List<Subscription> mDataList = getData;
if (mDataList.size() > 0) {
for (Subscription mSubscription : mDataList) {
if (mSubscription.isSub == true) {
Intent intent = new Intent(NotificationService.this,
AlamrReceiver.class);
intent.putExtra("data", (Serializable)mSubscription);
intent.setData(Uri.parse("custom://" + uniqueCode));
intent.setAction(String.valueOf(uniqueCode));
am = (AlarmManager) getSystemService(ALARM_SERVICE);
pi = PendingIntent.getBroadcast(
NotificationService.this, uniqueCode, intent,
PendingIntent.FLAG_CANCEL_CURRENT);
am.set(AlarmManager.RTC_WAKEUP, reminderTime, pi);
uniqueCode = uniqueCode + 1;
}
}
}
NotificationService.this.stopSelf();
}
};
}
2.Receive broadcast information and show Notification.
public class AlamrReceiver extends BroadcastReceiver {
private NotificationManager mNM;
#Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
mNM = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);
Subscription mSubscription = intent.getSerializableExtra("data");
if (mSubscription != null) {
showNotification(context, mSubscription);
}
}
private void showNotification(Context context, Subscription mSubscription) {
...
NotificationCompat.Builder builder = new NotificationCompat.Builder(
context);
builder.setContentTitle(text);
builder.setContentText(subTitleString + currencyString);
builder.setSmallIcon(Common.CATEGORY_ICON[cIcon]);
builder.setDefaults(Notification.DEFAULT_VIBRATE);
builder.setAutoCancel(true);
Intent intent = new Intent(context, BillDetailsActivity.class);
TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
stackBuilder.addParentStack(BillDetailsActivity.class);
intent.putExtra("dataMap", (Serializable) tMap);
stackBuilder.addNextIntent(intent);
PendingIntent contentIntent = stackBuilder.getPendingIntent(0,
PendingIntent.FLAG_UPDATE_CURRENT);
builder.setContentIntent(contentIntent);
int uniqueRequestCode = (int) System.currentTimeMillis();
mNM.notify(uniqueRequestCode, builder.build());
}
}
Do not forget BOOT_COMPLETED , when the phone restarted , start the service and check the database

I am not sure of concept of your app, but if you want to check whether user has subscribed for current month or not, you don't need to run a Service for that.
You should check this in Splash Screen or Main Activity of your app. But anyways,
if you still need to do this, i suggest to go with Service or AlarmManager.
BroadcastReceiver won't work alone, you need to trigger them on particular events according to your need.
Also if you use service, please keep in mind that Android MIGHT kill your service in low memory kind of situation.
So i'll suggest that you should go with AlarmManager, which will check for subscription status after specific time or something.
PS : i know this should be addded as comment, but i don't have enough reputations to comment so posted as answer

Techniques to implement a notification service

I have a main activity where the user can enable/disable notifications, set the notification interval, and set the base time the notification interval will use. Notifications will typically trigger about 2 hours from each other. After a certain time, an accumulator will reach a maximum value and notifications will no longer be needed.
What is the standard way of implementing such a notification scheme? I tried using a handler inside of a service using postAtTime, but it seems that there are a lot of conditions that can cause it to never run. I looked at a timer inside of the service, but putting the phone in standby will stop any timers, plus it just seems like a bad idea.
The only other option I came across I have yet to explore, but it involves using an AlarmManager and a BroadcastReceiver. Should I just ditch the service and schedule a repeating alarm instead? I need to be able to disable all remaining alarms once my accumulator has reached max value.
Thanks for any input.

What if you start a service that spawns a thread like this:
thread t = new thread(new Runnable(){
public void Run(){
boolean notified = false;
while( !notified ){
if( notify_time - time > 1000 ){
Thread.sleep(999);
else if( notify_time - time <= 0 ){
// START NOTIFICATION ACTIVITY
notified = true;
}
}
}
}
t.start();
I have not done anything like this personally, so I am not sure what service can do to notify the user or start an activity, but it does have the full panoply of options available to an activity, so yeah.
Oh but it just occured to me you'll need to use a handler for that because of the multithreaded aspect here.

Since I will always have a finite number of notifications and I can calculate the elapsed time in advance, it seems the combination of AlarmManager and a BroadcastReceiver work pretty well. Here is how I implemented this:
I first created a BroadcastReceiver
public class NotificationReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
//Get handle to system notification manager
NotificationManager mNM = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
//Get message from intent
Bundle bundle = intent.getExtras();
CharSequence text = bundle.getString("notification_message");
// Set the icon, scrolling text and timestamp
Notification notification = new Notification(R.drawable.notification_icon, text, System.currentTimeMillis());
// The PendingIntent to launch our activity if the user selects this notification
PendingIntent contentIntent = PendingIntent.getActivity(context, 0, new Intent(context, MainActivity.class), 0);
// Set the info for the views that show in the notification panel.
notification.setLatestEventInfo(context, context.getText(R.string.app_name),text, contentIntent);
// Set Flags
notification.flags |= Notification.FLAG_AUTO_CANCEL;
// Send the notification.
mNM.notify(R.string.notification, notification);
}
}
I then created a class that used a AlarmManager to create/cancel alarms that send a message to the BroadcastReceiver
public class NotificationSender {
private AlarmManager mAlarmManager;
private Context mContext;
private Intent mIntent;
public NotificationSender(Context context){
this.mAlarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
this.mIntent = new Intent(context, NotificationReceiver.class);
this.mContext = context;
}
public void setAlarm(Long etaMillis, int accumulator){
//Create intent to send to Receiver
this.mIntent.putExtra("notification_message","Message");
//Use accumulator as requestCode so we can cancel later
PendingIntent sender = PendingIntent.getBroadcast(this.mContext, accumulator, this.mIntent, PendingIntent.FLAG_UPDATE_CURRENT);
//Set Alarm
mAlarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, etaMillis, sender);
}
public void cancelAlarms(){
//requestCode (accumulator) will always be a multiple of 10 and less than 100
for (int x = 10; x <= 100; x += 10){
PendingIntent operation = PendingIntent.getBroadcast(this.mContext, x, this.mIntent, PendingIntent.FLAG_UPDATE_CURRENT);
mAlarmManager.cancel(operation);
}
}
public void createAlarms(PreferenceHelper prefs){
//Calculate time notifications are due and set an alarm for each one
//PreferenceHelper is a class to help pull values from shared preferences
Date currentTime = new Date();
for (int i = prefs.getNotificationInterval(); i <= 100; i += prefs.getNotificationInterval()) {
if (i > prefs.getAccumulator()) {
this.setAlarm(SystemClock.elapsedRealtime() + calculateETA(i, prefs).getTime() - currentTime.getTime(), i);
}
}
}
public void refreshAlarms(PreferenceHelper prefs){
this.cancelAlarms();
if (prefs.isNotificationsEnabled()) this.createAlarms(prefs);
}
}
The important part is to use the accumulator as the requestCode so we can cancel all of our alarms later.
Finally I used the NotificationSender class in my activity by calling refreshAlarms() in onCreate() and whenever the user modifies preferences that are relevant to scheduling notifications. Rebooting the phone will clear all alarms so the app must be restarted before notifications will begin. If the system happens to kills the process, the alarms will still trigger at the appropriate time.