Develop Reference

Alarm Manager not starting after 60 seconds

I'm trying to set my alarm manager working, just simple schedule, firing toast every minute, but it's not working, what's wrong with the code?
Main Activity :
public void klik(View view) {
startalarm();
}
public void startalarm(){
AlarmManager manager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
Intent intent;
PendingIntent pendingIntent;
intent = new Intent(this, AlarmToastReciever.class);
pendingIntent = PendingIntent.getBroadcast(this,0,intent,0);
manager.setRepeating(AlarmManager.RTC_WAKEUP, SystemClock.elapsedRealtime()+3000,+60000,pendingIntent);
}
}
AlarmToastReciever class :
public class AlarmToastReciever extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent){
Toast.makeText(context,"GOWNO", Toast.LENGTH_SHORT).show();
}
}

As stated in documentation
As of Android 4.4 (API Level 19), all repeating alarms are inexact. Note that while setInexactRepeating() is an improvement over setRepeating(), it can still overwhelm a server if every instance of an app hits the server around the same time. Therefore, for network requests, add some randomness to your alarms, as discussed above.
You can use "setInexactRepeating()" or set an exact one time alarm then set next alarm in On Receive method
Also make sure you added your receiver to the manifest file, between application tag, like
<receiver android:name=".AlarmToastReciever"
android:enabled="true">
<intent-filter>
</intent-filter>
</receiver>

Use this code to initialize alarm manager.
public void setupAlarm() {
final Calendar calNow = Calendar.getInstance();
final Calendar calSet = (Calendar) calNow.clone();
calSet.set(Calendar.HOUR_OF_DAY, calNow.get(Calendar.HOUR_OF_DAY));
calSet.set(Calendar.MINUTE, calNow.get(Calendar.MINUTE) + 1);
calSet.set(Calendar.SECOND, calNow.get(Calendar.SECOND));
final Intent intent = new Intent(this, UploadStarterReceiver.class);
final PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 1,
intent, 0);
final AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, calSet.getTimeInMillis(),
60 * 1000, pendingIntent);
}

Alarm successfully sets for future time, but not for Calendar date

I have this app where i want to set a notification on a specific date the user defines. I saw lots of code and relative answers here on SO but for some reason nothing works so far.
In this test project i have 2 methods. One that sets an alarm to ring 5 seconds on future and one that assigns the desired date.
Problem:
If i set the alarm to a second delay it works fine. The notification is shown within 5 seconds after the alarm assignment. But if i use the method that passes a Calendar date, it does nothing. Not triggers no notification
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void setAlarmOnClick(View view){
// this method call works fine
setAlarm(getNotification("Date test"), 3000);
// this one doesn't
// setAlarm(getNotification("Date test"), getDate());
}
// Here nothing happens when the date comes
private void setAlarm(Notification notification, Calendar cal) {
Intent notificationIntent = new Intent(this, NotificationPublisher.class);
notificationIntent.putExtra(NotificationPublisher.NOTIFICATION_ID, 1);
notificationIntent.putExtra(NotificationPublisher.NOTIFICATION, notification);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT | Intent.FILL_IN_DATA);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),pendingIntent );
Toast.makeText(this, "Alarm worked.", Toast.LENGTH_LONG).show();
}
// This alarm get successfully trigger here showing the notification
private void setAlarm(Notification notification, int delay) {
Intent notificationIntent = new Intent(this, NotificationPublisher.class);
notificationIntent.putExtra(NotificationPublisher.NOTIFICATION_ID, 1);
notificationIntent.putExtra(NotificationPublisher.NOTIFICATION, notification);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT | Intent.FILL_IN_DATA);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, delay, pendingIntent );
Toast.makeText(this, "Alarm worked.", Toast.LENGTH_LONG).show();
}
private Calendar getDate(){
Calendar cal=Calendar.getInstance();
cal.set(Calendar.MONTH,8);
cal.set(Calendar.YEAR,2017);
cal.set(Calendar.DAY_OF_MONTH,29);
cal.set(Calendar.HOUR_OF_DAY,11);
cal.set(Calendar.MINUTE,47);
return cal;
}
#TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private Notification getNotification(String content) {
Notification.Builder builder = new Notification.Builder(this);
builder.setContentTitle("Scheduled Notification");
builder.setContentText(content);
builder.setSmallIcon(R.mipmap.ic_launcher);
return builder.build();
}
}
NotificationPublisher.java
public class NotificationPublisher extends BroadcastReceiver {
public static String NOTIFICATION_ID = "notification-id";
public static String NOTIFICATION = "notification";
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "Alarm worked.", Toast.LENGTH_LONG).show();
int id = intent.getIntExtra(NOTIFICATION_ID, 0);
NotificationManager notofManager = (NotificationManager)context. getSystemService(Context.NOTIFICATION_SERVICE);
Notification notification = intent.getParcelableExtra(NOTIFICATION);
notofManager.notify(id, notification);
}
}
I would really appreciate anykind of help!
P.S.
How can i be sure that an alarm was successfully set on a date. Even if a code works and a date is set a week form now. How can i test that it will trigger then? Obviously we can't wait a week to see that. Changing the device date is working? Thank you

Calendar month goes from 0-11 instead of 1-12 as u assumed.
So something like:
cal.set(Calendar.Month, 7 );
would set your calendar month to August.

AlarmManager executed even if the time is wrong

I am using the following code to execute the Alarm at 10:30 AM and then keep executing every 8seconds, but the problem is, this code execute the Alarm manager even when the time is not 10:30.
I have tried everything but the code keep executing the Alarm regardless of what time is set,
public class MainActivity extends Activity {
private PendingIntent pendingIntent;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/* Retrieve a PendingIntent that will perform a broadcast */
Intent alarmIntent = new Intent(MainActivity.this, AlarmReceiver.class);
pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 0, alarmIntent, 0);
startAt10();
}
public void startAt10() {
AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
/* Set the alarm to start at 10:30 AM */
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, 10);
calendar.set(Calendar.MINUTE, 30);
/* Repeating on every 8 seconds interval */
manager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
1000 * 8, pendingIntent);
}
}
and this is my AlarmReceiver class,
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// For our recurring task, we'll just display a message
Toast.makeText(context, "Welcome Back ! ", Toast.LENGTH_SHORT).show();
}
I have also added this in my AndroidManifest.xml,
<receiver android:name="com.example.test2.AlarmReceiver" android:enabled="true" >
</receiver>
How to make it to only execute at 10:30AM ?

Your code is correct. The alarm will start at 10:30 am and repeats at every 8 seconds. But once check the time in the device or emulator in which your app is running. If the time is already past then the alarm starts executing immediately.
If the time is not completed then once uninstall the application and run again it may work.

Setting a repeating alarm in android

I am trying to set a repeating alarm in android that eventually will go up at a user specified time. However the alarm goes off right away when once it is set, even when I make sure the alarm isn't set to go off until after the alarm has been set. For example, I have the code below set to have an alarm go off at 10:43 so I set the alarm at 10:41, but the alarm goes off right away. Any ideas? Thanks in advance.
public class Alarm extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
PowerManager pm = (PowerManager) context
.getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(
PowerManager.PARTIAL_WAKE_LOCK, "");
wl.acquire();
Toast.makeText(context, "Alarm !!!!!!!!!!", Toast.LENGTH_LONG).show(); // For
Intent scheduledIntent = new Intent(context,ReminderMessage.class);
scheduledIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(scheduledIntent);
// example
wl.release();
}
public void SetAlarm(Context context) {
AlarmManager am = (AlarmManager) context
.getSystemService(Context.ALARM_SERVICE);
Date dat = new Date();
Calendar cal_alarm = Calendar.getInstance();
Calendar cal_now = Calendar.getInstance();
cal_now.setTime(dat);
cal_alarm.setTime(dat);
cal_alarm.set(Calendar.HOUR_OF_DAY, 10);
cal_alarm.set(Calendar.MINUTE, 43);
cal_alarm.set(Calendar.SECOND, 0);
if(cal_alarm.before(cal_now)){
cal_alarm.add(Calendar.DATE, 1);
}
Intent i = new Intent(context, Alarm.class);
PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0);
am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), cal_alarm.getTimeInMillis() , pi); // Millisec * Second * Minute
}
public void CancelAlarm(Context context) {
Intent intent = new Intent(context, Alarm.class);
PendingIntent sender = PendingIntent
.getBroadcast(context, 0, intent, 0);
AlarmManager alarmManager = (AlarmManager) context
.getSystemService(Context.ALARM_SERVICE);
alarmManager.cancel(sender);
}
}

I think your line:
am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), cal_alarm.getTimeInMillis() , pi); // Millisec * Second * Minute
is triggering the alarm immediately, the second param is the scheduled time, and the third is the period. So if you wanted your alarm to go off at cal_alarm time, you want to use something like:
am.setRepeating(AlarmManager.RTC_WAKEUP, cal_alarm.getTimeInMillis(), 1000*60*5 , pi); // Millisec * Second * Minute
That should go off at the cal_alarm time, and repeat every 5 mins.
AlarmManager.SetRepeating API Doc

Android: How to use AlarmManager

I need to trigger a block of code after 20 minutes from the AlarmManager being set.
Can someone show me sample code on how to use an AlarmManager in ِAndroid?
I have been playing around with some code for a few days and it just won't work.

"Some sample code" is not that easy when it comes to AlarmManager.
Here is a snippet showing the setup of AlarmManager:
AlarmManager mgr=(AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Intent i=new Intent(context, OnAlarmReceiver.class);
PendingIntent pi=PendingIntent.getBroadcast(context, 0, i, 0);
mgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime(), PERIOD, pi);
In this example, I am using setRepeating(). If you want a one-shot alarm, you would just use set(). Be sure to give the time for the alarm to start in the same time base as you use in the initial parameter to set(). In my example above, I am using AlarmManager.ELAPSED_REALTIME_WAKEUP, so my time base is SystemClock.elapsedRealtime().
Here is a larger sample project showing this technique.

There are some good examples in the android sample code
.\android-sdk\samples\android-10\ApiDemos\src\com\example\android\apis\app
The ones to check out are:
AlarmController.java
OneShotAlarm.java
First of, you need a receiver, something that can listen to your alarm when it is triggered. Add the following to your AndroidManifest.xml file
<receiver android:name=".MyAlarmReceiver" />
Then, create the following class
public class MyAlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "Alarm went off", Toast.LENGTH_SHORT).show();
}
}
Then, to trigger an alarm, use the following (for instance in your main activity):
AlarmManager alarmMgr = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(this, MyAlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
Calendar time = Calendar.getInstance();
time.setTimeInMillis(System.currentTimeMillis());
time.add(Calendar.SECOND, 30);
alarmMgr.set(AlarmManager.RTC_WAKEUP, time.getTimeInMillis(), pendingIntent);
.
Or, better yet, make a class that handles it all and use it like this
Bundle bundle = new Bundle();
// add extras here..
MyAlarm alarm = new MyAlarm(this, bundle, 30);
this way, you have it all in one place (don't forget to edit the AndroidManifest.xml)
public class MyAlarm extends BroadcastReceiver {
private final String REMINDER_BUNDLE = "MyReminderBundle";
// this constructor is called by the alarm manager.
public MyAlarm(){ }
// you can use this constructor to create the alarm.
// Just pass in the main activity as the context,
// any extras you'd like to get later when triggered
// and the timeout
public MyAlarm(Context context, Bundle extras, int timeoutInSeconds){
AlarmManager alarmMgr =
(AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, MyAlarm.class);
intent.putExtra(REMINDER_BUNDLE, extras);
PendingIntent pendingIntent =
PendingIntent.getBroadcast(context, 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
Calendar time = Calendar.getInstance();
time.setTimeInMillis(System.currentTimeMillis());
time.add(Calendar.SECOND, timeoutInSeconds);
alarmMgr.set(AlarmManager.RTC_WAKEUP, time.getTimeInMillis(),
pendingIntent);
}
#Override
public void onReceive(Context context, Intent intent) {
// here you can get the extras you passed in when creating the alarm
//intent.getBundleExtra(REMINDER_BUNDLE));
Toast.makeText(context, "Alarm went off", Toast.LENGTH_SHORT).show();
}
}

What you need to do is first create the intent you need to schedule. Then obtain the pendingIntent of that intent. You can schedule activities, services and broadcasts. To schedule an activity e.g MyActivity:
Intent i = new Intent(getApplicationContext(), MyActivity.class);
PendingIntent pi = PendingIntent.getActivity(getApplicationContext(),3333,i,
PendingIntent.FLAG_CANCEL_CURRENT);
Give this pendingIntent to alarmManager:
//getting current time and add 5 seconds in it
Calendar cal = Calendar.getInstance();
cal.add(Calendar.SECOND, 5);
//registering our pending intent with alarmmanager
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP,cal.getTimeInMillis(), pi);
Now MyActivity will be launched after 5 seconds of the application launch, no matter you stop your application or device went in sleep state (due to RTC_WAKEUP option).
You can read complete example code Scheduling activities, services and broadcasts #Android

I wanted to comment but <50 rep, so here goes. Friendly reminder that if you're running on 5.1 or above and you use an interval of less than a minute, this happens:
Suspiciously short interval 5000 millis; expanding to 60 seconds
See here.

Some sample code when you want to call a service from the Alarmmanager:
PendingIntent pi;
AlarmManager mgr;
mgr = (AlarmManager)ctx.getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(DataCollectionActivity.this, HUJIDataCollectionService.class);
pi = PendingIntent.getService(DataCollectionActivity.this, 0, i, 0);
mgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() , 1000, pi);
You dont have to ask userpermissions.

An AlarmManager is used to trigger some code at a specific time.
To start an Alarm Manager you need to first get the instance from the System. Then pass the PendingIntent which would get executed at a future time that you specify
AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent alarmIntent = new Intent(context, MyAlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, alarmIntent, 0);
int interval = 8000; //repeat interval
manager.setInexactRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), interval, pendingIntent);
You need to be careful while using the Alarm Manager.
Normally, an alarm manager cannot repeat before a minute. Also in low power mode, the duration can increase to up to 15 minutes.