java - how to cancel method of count down timer to stop working -

i have list of music user set time play. want have button cancel m count down timer . test way doesn't work @ all. here code play , set time play.

public class main extends activity {

public static int hour_device, minute_device; public static int hour_user, minute_user; splash splash; listview listview; adaptor adaptor; private mediaplayer mediaplayer; static view lastview = null; static myindexstore indexstore;  list<string> lines1 = new arraylist<string>(); list<string> lines2 = new arraylist<string>(); static list<string> array_audio = new arraylist<string>();  inputstream in; bufferedreader reader; string line = "1"; string[] tracks; string[] names; string[] infos; @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     indexstore = new myindexstore(getapplicationcontext());     setcontentview(r.layout.main_activity);       splash = new splash(this);     splash.set_identity("1");       initiate();     mediaplayer = mediaplayer.create(getapplicationcontext(), r.raw.a1);     //lastview = null;     listview = (listview) findviewbyid(r.id.list);     readtext1();     names = lines1.toarray(new string[0]);// = {"track one","the seconnd track","a nice track","name name name","the seconnd track","a nice track","name name name"};     readtext2();     infos = lines2.toarray(new string[0]);     tracks = array_audio.toarray(new string[0]);     adaptor = new adaptor(getapplicationcontext(), tracks, names, infos);     listview.setadapter(adaptor);     mediaplayer.setoncompletionlistener(new oncompletionlistener() {          @override         public void oncompletion(mediaplayer arg0) {             if (lastview != null) {                 imageview play = (imageview) lastview.findviewbyid(r.id.play_stop);                 play.setimageresource(r.drawable.n_btn_play_unselected);             }         }     }); }  private static void initiate() {     field[] fields = r.raw.class.getfields();     array_audio.clear();     (int count = 0; count < fields.length; count++) {         array_audio.add("a" + (count + 1));     } }  private void play(int index) {     mediaplayer.release();     index++;     string s = "a" + index;     resources resources = getresources();     final int resourceid = resources.getidentifier(s, "raw", getpackagename());      try {         mediaplayer = mediaplayer.create(this, resourceid);         mediaplayer.start();     } catch (exception e) {         e.printstacktrace();     }  }  @override protected void onpause() {     mediaplayer.release();     listview.invalidateviews();     super.onpause(); }   private void readtext1() {     lines1.clear();     line = "1";     try {         in = this.getassets().open("names.txt");         reader = new bufferedreader(new inputstreamreader(in));         while (line != null) {             line = reader.readline();             if (line != null)                 lines1.add(line);             else                 break;         }      } catch (ioexception e) {         e.printstacktrace();     } }  private void readtext2() {     lines2.clear();     line = "1";     try {         in = this.getassets().open("infos.txt");         reader = new bufferedreader(new inputstreamreader(in));         while (line != null) {             line = reader.readline();             if (line != null)                 lines2.add(line);             else                 break;         }      } catch (ioexception e) {         e.printstacktrace();     } }   public class adaptor extends arrayadapter<string> {      private final context context;     private final string[] tracks;     private final string[] names;     private final string[] infos;     private hashmap<integer,string> textmap;     typeface type_face;       public adaptor(context context, string[] tracks, string[] names, string[] infos) {         super(context, r.layout.track, tracks);         this.context = context;         this.tracks = tracks;         this.names = names;         this.infos = infos;         type_face = typeface.createfromasset(context.getassets(), "btitrbd.ttf");         this.textmap = new hashmap<>();     }      @override     public view getview(final int position, view convertview, viewgroup parent) {         layoutinflater inflater = (layoutinflater) context.getsystemservice(context.layout_inflater_service);         final view rowview = inflater.inflate(r.layout.track, parent, false);          textview name = (textview) rowview.findviewbyid(r.id.track_name);         final textview time = (textview) rowview.findviewbyid(r.id.time);         //populate textview map         if(textmap!=null && textmap.get(new integer(position))!=null){             time.settext(textmap.get(new integer(position)));         }         name.settext(names[position]);         name.settypeface(type_face);         name.settypeface(type_face);         final imageview ringtone = (imageview) rowview.findviewbyid(r.id.ringtone);         if (position == indexstore.getindex())             ringtone.setimageresource(r.drawable.n_btn_ringtone_seted);         final imageview play = (imageview) rowview.findviewbyid(r.id.play_stop);         ringtone.setonclicklistener(new onclicklistener() {              @override             public void onclick(view arg0) {                  layoutinflater factory = layoutinflater.from(main.this);                 final view deletedialogview = factory.inflate(                         r.layout.mylayout, null);                 final alertdialog deletedialog = new alertdialog.builder(main.this).create();                 deletedialog.setview(deletedialogview);                  textview device_time = (textview) deletedialogview.findviewbyid(r.id.current_time);                 calendar c = calendar.getinstance();                 int hour = c.get(calendar.hour_of_day);                 int minute = c.get(calendar.minute);                 hour_device = hour;                 minute_device = minute;                 device_time.settext(hour_device + ":" + minute_device);                  deletedialogview.findviewbyid(r.id.set).setonclicklistener(new onclicklistener() {                      @override                     public void onclick(view v) {                          timepicker timepicker = (timepicker) deletedialogview.findviewbyid(r.id.timepicker);                         timepicker.setis24hourview(true);                         hour_user = timepicker.getcurrenthour();                         minute_user = timepicker.getcurrentminute();                         string time1 = hour_device + ":" + minute_device;                         string time2 = hour_user + ":" + minute_user;                         simpledateformat format = new simpledateformat("hh:mm");                         date date1 = null;                         try {                             date1 = format.parse(time1);                         } catch (parseexception e) {                             e.printstacktrace();                         }                         date date2 = null;                         try {                             date2 = format.parse(time2);                         } catch (parseexception e) {                             e.printstacktrace();                         }                         long result = date2.gettime() - date1.gettime();                           new countdowntimer(result, 1000) {                              public void ontick(long millisuntilfinished) {                                 time.settext(("seconds remaining: " + millisuntilfinished / 1000));                                 //create hashmap<integer,string> textmap @ constructer of adapter                                 //now fill info int'o                                 textmap.put(new integer(position), "seconds remaining: " + millisuntilfinished / 1000);                                 //notify data change                                 notifydatasetchanged();                              }                              public void onfinish() {                                 time.setvisibility(view.invisible);                                 //create hashmap<integer,string> textmap @ constructer of adapter                                 //now fill info                                 textmap.put(new integer(position),null);                                 //notify data change                                 notifydatasetchanged();                                 toast.maketext(getapplicationcontext(), "finish", toast.length_long).show();                                 if (rowview != lastview || mediaplayer == null) {                                     play(position);                                     if (lastview != null)                                         lastview = rowview;                                 } else {                                     play.setimageresource(r.drawable.n_btn_play_unselected);                                     mediaplayer.release();                                     lastview = null;                                 }                               }                          }.start();                         deletedialog.dismiss();                     }                 });                   deletedialog.show();               }         });          play.setonclicklistener(new onclicklistener() {              @override             public void onclick(view arg0) {                 if (rowview != lastview || mediaplayer == null) {                     play(position);                     if (lastview != null)                         lastview = rowview;                 } else {                     play.setimageresource(r.drawable.n_btn_play_unselected);                     mediaplayer.release();                      lastview = null;                 }             }         });         return rowview;     }      } 

}

make count down timer instance variable;

private countdowntimer timer; 

then delegate count variable:

@override public void onclick(view v) {     ...     timer = new countdowntimer(result, 1000) {         ...     } } 

now can stop timer whenever want to:

timer.cancel();