scheduled notification on android studio app. alarmManager.set doesn't work -

that's code scheduled notification android app, nothing reason. please tell me problem. question: made button send notification - learning, , reason works on samsung s6. when run app on android studio emulator gives me error notification package. why that? thank lot!

public void setalarm(view view) {         long alerttime = new gregoriancalendar().gettimeinmillis()+5*1000;          intent alertintent = new intent(this, alertreceiver.class);          alarmmanager alarmmanager = (alarmmanager)                 getsystemservice(context.alarm_service);          alarmmanager.set(alarmmanager.rtc_wakeup, alerttime,                 pendingintent.getbroadcast(this, 1, alertintent, pendingintent.flag_update_current));     } }   public class alertreceiver extends broadcastreceiver {       @override     public void onreceive(context context, intent intent) {          createnotification(context, "time up", "5 seconds has passed", "alert");     }      public void createnotification(context context, string msg, string msgtext, string msgalert) {          pendingintent noficitintent = pendingintent.getactivity(context, 0,                 new intent(context, mainactivity.class), 0);          notificationcompat.builder mbuilder = new notificationcompat.builder(context)                 .setsmallicon(r.drawable.ic_launcher)                 .setcontenttitle(msg)                 .setticker(msgalert)                 .setcontenttext(msgtext);          mbuilder.setcontentintent(noficitintent);          mbuilder.setdefaults(notificationcompat.default_sound);          mbuilder.setautocancel(true);          notificationmanager mnotificationmanager =                 (notificationmanager) context.getsystemservice(context.notification_service);          mnotificationmanager.notify(1, mbuilder.build());      } } 

based on comments, seems forgot register broadcastreceiver. per android docs able receive intents on receiver if register first:

you can either dynamically register instance of class context.registerreceiver() or statically declare implementation tag in androidmanifest.xml.

since sending broadcast directly receiver that:

intent alertintent = new intent(this, alertreceiver.class); 

there no point in declaring intent-filter it, need add following line androidmanifest.xml (inside <application> tag):

<receiver android:name="com.your.package.alertreceiver" /> 

hope helps.