java - Android alarm manager does not wait -

i try start simple method every 20 seconds, idea start alarm in method again. create class again, in method executed , starting alarm... , on method should create notification.

public class createnotification extends broadcastreceiver{     public void onreceive(context context, intent intent) {          dostuff();              notificationcompat.builder mnotebuilder =                     new notificationcompat.builder(context)                             .setsmallicon(r.drawable.icon)                             .setcontenttitle("...")                             .setcontenttext(shownstring)              //get instance of notificationmanager service             notificationmanager mnotifymgr = (notificationmanager) context.getsystemservice(context.notification_service);             //build notification             mnotifymgr.notify(mnotificationid, mnotebuilder.build());              createnewalarm(context);     }          private void createnewalarm(context context){             intent alarmintent = new intent(context, createnotification.class);             pendingintent pendingintent = pendingintent.getbroadcast(context, 0, alarmintent, 0);             alarmmanager manager = (alarmmanager) context.getsystemservice(context.alarm_service);             manager.set(alarmmanager.rtc_wakeup, 20000, pendingintent);     } } 

this started in main activity:

    intent alarmintent = new intent(this, createnotification.class);     pendingintent pendingintent = pendingintent.getbroadcast(this, 0, alarmintent, 0);     alarmmanager manager = (alarmmanager) getsystemservice(alarm_service);     manager.set(alarmmanager.rtc_wakeup, 4000, pendingintent); 

now problem is, don't expected result, new notification every 20 seconds, creates time notification, fast processor allows. there no break in between , alarmmanager seems not schedule anything, creates class instantly.

thanks lot help!

manager.set(alarmmanager.rtc_wakeup, system.currenttimemillis()+20000, pendingintent); 

your solution: 20000 = 1970. january 1. 0:00:20 have add millisec current time. (another solution current time.)

calendar calendar = calendar.getinstance(); calendar.gettimeinmillis()+yourtimeinmillis;