Scheduling recurring task in Android

Question

I m designing an app that has a recurring task of sending presence to a dedicated server as long as the app is in foreground   In my searches across the web I saw a few different approaches and wanted to know what is the best way of doing this   What is the best way to schedule a server call   The options I saw were    Timer   ScheduledThreadPoolExecutor  Service  BroadcastReciever with AlarmManager    What s your opinion   EDIT   The reason I need this is for a chat based app that sends all the user actions to a remote server  i e  user is typing a message  user is reading a message  user is online  user is offline etc   This means that once every interval  I need to send the server what I m doing  since I open a chat room with other people  they need to know what I m doing   Similar to the whatsapp message feedback mechanism    EDIT  2    Recurring tasks should now be scheduled almost always via the JobScheduler API  or FirebaseJobDispatcher for lower APIs  in order to prevent battery draining issues as can be read in the vitals section of the Android training  EDIT  3    FirebaseJobDispatcher has been deprecated and replaced by Workmanager  which also incorporates features of JobScheduler

User · Answer

Quoting the Scheduling Repeating Alarms - Understand the Trade-offs docs:

A common scenario for triggering an operation outside the lifetime of your app is syncing data with a server. This is a case where you might be tempted to use a repeating alarm. But if you own the server that is hosting your app's data, using Google Cloud Messaging (GCM) in conjunction with sync adapter is a better solution than AlarmManager. A sync adapter gives you all the same scheduling options as AlarmManager, but it offers you significantly more flexibility.

So, based on this, the best way to schedule a server call is using Google Cloud Messaging (GCM) in conjunction with sync adapter.

User · Answer

I have created on time task in which the task which user wants to repeat  add in the Custom TimeTask run   method  it is successfully reoccurring    import java text SimpleDateFormat   import java util Calendar   import java util Timer   import java util TimerTask    import android os Bundle   import android view View   import android view View OnClickListener   import android widget Button   import android widget CheckBox   import android widget TextView   import android app Activity   import android content Intent    public class MainActivity extends Activity         CheckBox optSingleShot       Button btnStart  btnCancel       TextView textCounter        Timer timer       MyTimerTask myTimerTask        int tobeShown   0      Override protected void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout activity main        optSingleShot    CheckBox findViewById R id singleshot       btnStart    Button findViewById R id start       btnCancel    Button findViewById R id cancel       textCounter    TextView findViewById R id counter       tobeShown   1       if timer    null           timer cancel                 re-schedule timer here       otherwise  IllegalStateException of        TimerTask is scheduled already         will be thrown     timer   new Timer        myTimerTask   new MyTimerTask         if optSingleShot isChecked               singleshot delay 1000 ms         timer schedule myTimerTask  1000        else            delay 1000ms  repeat in 5000ms         timer schedule myTimerTask  1000  1000              btnStart setOnClickListener new OnClickListener              Override         public void onClick View arg0                  Intent i   new Intent MainActivity this  ActivityB class               startActivity i                  if timer    null                   timer cancel                                 re-schedule timer here               otherwise  IllegalStateException of                TimerTask is scheduled already                 will be thrown             timer   new Timer                myTimerTask   new MyTimerTask                 if optSingleShot isChecked                       singleshot delay 1000 ms                 timer schedule myTimerTask  1000                else                    delay 1000ms  repeat in 5000ms                 timer schedule myTimerTask  1000  1000                                     btnCancel setOnClickListener new OnClickListener              Override         public void onClick View v                if  timer  null                   timer cancel                    timer   null                                       Override protected void onResume         super onResume         if timer    null           timer cancel                 re-schedule timer here       otherwise  IllegalStateException of        TimerTask is scheduled already         will be thrown     timer   new Timer        myTimerTask   new MyTimerTask         if optSingleShot isChecked               singleshot delay 1000 ms         timer schedule myTimerTask  1000        else            delay 1000ms  repeat in 5000ms         timer schedule myTimerTask  1000  1000              Override protected void onPause         super onPause         if  timer  null           timer cancel            timer   null             Override protected void onStop         super onStop         if  timer  null           timer cancel            timer   null            class MyTimerTask extends TimerTask         Override     public void run              Calendar calendar   Calendar getInstance            SimpleDateFormat simpleDateFormat                    new SimpleDateFormat  dd MMMM yyyy HH mm ss a            final String strDate   simpleDateFormat format calendar getTime              runOnUiThread new Runnable                  Override             public void run                     textCounter setText strDate

User · Answer

Timer  As mentioned on the javadocs you are better off using a ScheduledThreadPoolExecutor   ScheduledThreadPoolExecutor  Use this class when your use case requires multiple worker threads and the sleep interval is small  How small   Well  I d say about 15 minutes  The AlarmManager starts schedule intervals at this time and it seems to suggest that for smaller sleep intervals this class can be used  I do not have data to back the last statement  It is a hunch   Service  Your service can be closed any time by the VM  Do not use services for recurring tasks  A recurring task can start a service  which is another matter entirely   BroadcastReciever with AlarmManager  For longer sleep intervals   15 minutes   this is the way to go  AlarmManager already has constants   AlarmManager INTERVAL DAY   suggesting that it can trigger tasks several days after it has initially been scheduled  It can also wake up the CPU to run your code   You should use one of those solutions based on your timing and worker thread needs

User · Answer

I am not sure but as per my knowledge I share my views  I always accept best answer if I am wrong   Alarm Manager The Alarm Manager holds a CPU wake lock as long as the alarm receiver s onReceive   method is executing  This guarantees that the phone will not sleep until you have finished handling the broadcast  Once onReceive   returns  the Alarm Manager releases this wake lock  This means that the phone will in some cases sleep as soon as your onReceive   method completes  If your alarm receiver called Context startService    it is possible that the phone will sleep before the requested service is launched  To prevent this  your BroadcastReceiver and Service will need to implement a separate wake lock policy to ensure that the phone continues running until the service becomes available  Note  The Alarm Manager is intended for cases where you want to have your application code run at a specific time  even if your application is not currently running  For normal timing operations  ticks  timeouts  etc  it is easier and much more efficient to use Handler  Timer timer   new Timer         timer scheduleAtFixedRate new TimerTask              synchronized public void run                     here your todo                            TimeUnit MINUTES toMillis 1   TimeUnit MINUTES toMillis 1     Timer has some drawbacks that are solved by ScheduledThreadPoolExecutor  So it s not the best choice ScheduledThreadPoolExecutor  You can use java util Timer or ScheduledThreadPoolExecutor  preferred  to schedule an action to occur at regular intervals on a background thread  Here is a sample using the latter  ScheduledExecutorService scheduler       Executors newSingleThreadScheduledExecutor     scheduler scheduleAtFixedRate        new Runnable              public void run                    call service                     0  10  TimeUnit MINUTES    So I preferred ScheduledExecutorService But Also think about that if the updates will occur while your application is running  you can use a Timer  as suggested in other answers  or the newer ScheduledThreadPoolExecutor  If your application will update even when it is not running  you should go with the AlarmManager   The Alarm Manager is intended for cases where you want to have your application code run at a specific time  even if your application is not currently running   Take note that if you plan on updating when your application is turned off  once every ten minutes is quite frequent  and thus possibly a bit too power consuming

User · Answer

I realize this is an old question and has been answered but this could help someone  In your activity  private ScheduledExecutorService scheduleTaskExecutor    In onCreate    scheduleTaskExecutor   Executors newScheduledThreadPool 5          Schedule a task to run every 5 seconds  or however long you want      scheduleTaskExecutor scheduleAtFixedRate new Runnable              Override         public void run                    Do stuff here               runOnUiThread new Runnable                      Override                 public void run                            Do stuff to update UI here                      Toast makeText MainActivity this   Its been 5 seconds   Toast LENGTH SHORT  show                                                        0  5  TimeUnit SECONDS      or  MINUTES   HOURS etc

[android] Scheduling recurring task in Android

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