Android detect new day.

Some app like calendar need to update when system time change, we need to detect new day.

Declare variables.

int con = 0;

PendingIntent pi;

BroadcastReceiver br;

AlarmManager am;

Create function like this.

private void setup() {

          br = new BroadcastReceiver() {

               @Override

               public void onReceive(Context c, Intent i) {

                     //Update data here.

               }

          };

          registerReceiver(br, new IntentFilter("com.example.vidu"));

          pi = PendingIntent.getBroadcast(this, 0, new Intent("com.example.vidu"),0);

am = (AlarmManager) (this.getSystemService(Context.ALARM_SERVICE));

am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,

SystemClock.elapsedRealtime() + con, 86400000, pi);

}

In onCreate() we calculate wait time and call function like this.

String p = new Date().toString();

          p = p.trim();

          String a[] = p.split(" ");

          String a1[] = a[3].split(":");

          int b = Integer.parseInt(a1[0]);

          int g = Integer.parseInt(a1[1]);

          int g2 = Integer.parseInt(a1[2]);

          int pu = b * 60 * 60 + g * 60+g2;

          pu = pu * 1000;

          con = 86400000 - pu;

          setup();

Now when open app, alarm will run at 12 o’ clock at night, and after 24 hours mean next day it will run update again.

This way doesn’t affect battery because it minimize check times.

Remember to declare service in file Manifest.xml

<service

            android:name=".myservice"

            android:enabled="true"

            android:exported="false" />

And destroy when exit class.

@Override

     protected void onDestroy() {

super.onDestroy();

     am.cancel(pi);

     unregisterReceiver(br);  

     }