I'm refactoring some code so that my app will pull data from a website once a day at a given time. From my research, it seems like AlarmManager
is the most appropriate approach.
The tutorial I have been following is: http://mobile.tutsplus.com/tutorials/android/android-fundamentals-downloading-data-with-services/
So far, AlarmManager
and the BroadcastReceiver
seem to be working, however the Service
never seems to start (ie. onStartCommand
doesn't seem to be called)
Here are the important snippets of the code I have so far:
MyActivity.java
private void setRecurringAlarm(Context context) {
Calendar updateTime = Calendar.getInstance();
updateTime.setTimeZone(TimeZone.getDefault());
updateTime.set(Calendar.HOUR_OF_DAY, 20);
updateTime.set(Calendar.MINUTE, 30);
Intent downloader = new Intent(context, AlarmReceiver.class);
downloader.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, downloader, PendingIntent.FLAG_CANCEL_CURRENT);
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
// should be AlarmManager.INTERVAL_DAY (but changed to 15min for testing)
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, updateTime.getTimeInMillis(), AlarmManager.INTERVAL_FIFTEEN_MINUTES, pendingIntent);
Log.d("MyActivity", "Set alarmManager.setRepeating to: " + updateTime.getTime().toLocaleString());
}
AlarmReceiver.java
public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Intent dailyUpdater = new Intent(context, MyService.class);
context.startService(dailyUpdater);
Log.d("AlarmReceiver", "Called context.startService from AlarmReceiver.onReceive");
}
}
MyService.java
public class MyService extends Service {
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.d("MyService", "About to execute MyTask");
new MyTask().execute();
return Service.START_FLAG_REDELIVERY;
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
private class MyTask extends AsyncTask<String, Void, boolean> {
@Override
protected boolean doInBackground(String... strings) {
Log.d("MyService - MyTask", "Calling doInBackground within MyTask");
return false;
}
}
}
AndroidManifest.xml
<application ...>
...
<service android:name="MyService"></service>
<receiver android:name="AlarmReceiver"></receiver>
</application>
When I trigger the setRecurringAlarm
in MyActivity
the log prints as expected, similarly, every 15min the log from AlarmReceiver
appears. However, I never see the log from MyService
:(
Example of what I see in the logs:
DEBUG/MyActivity(688): Set alarmManager.setRepeating to: Jan 29, 2012 8:30:06 PM
DEBUG/AlarmReceiver(688): Called context.startService from AlarmReceiver.onReceive
DEBUG/AlarmReceiver(688): Called context.startService from AlarmReceiver.onReceive
Can't seem to figure out what I've done wrong - my understanding from the Android Dev Docs is that in AlarmReceiver
when I call context.startService(dailyUpdater)
that should in turn call onStartCommand
in MyService
, though that doesn't seem to be the case!
What am I doing wrong that is causing MyService
to not start at all?
Figured it out!
MyService should be extending IntentService instead of Service!
With this change, it also means that instead of overriding onStartCommand
should be overriding onHandleIntent
instead (see docs on IntentService)
So MyService now looks like this:
public class MyService extends IntentService {
public MyService() {
super("MyServiceName");
}
@Override
protected void onHandleIntent(Intent intent) {
Log.d("MyService", "About to execute MyTask");
new MyTask().execute();
}
private class MyTask extends AsyncTask<String, Void, boolean> {
@Override
protected boolean doInBackground(String... strings) {
Log.d("MyService - MyTask", "Calling doInBackground within MyTask");
return false;
}
}
}
Note: From the docs, the default implementation of onBind
returns null
so no need to override it.
More information about extending IntentService
: http://developer.android.com/guide/topics/fundamentals/services.html#ExtendingIntentService