web services - How to refresh the value of any object in previous stacked Activity's Adapter in android -

i working on music app in user getting mp3 file webservice api. when selecting song in adapter class, getting selectionpositions value , sending in next activity(playsong) using intent. in next activity having layout of music player starts playing song.

here adapter class.

 public class albumnlistadapter  extends baseadapter {     context cxt;     arraylist<albumnlistdata>arr;     private mediaplayer mediaplayer;     public textview songname, duration;     private double timeelapsed = 0, finaltime = 0;     private int forwardtime = 2000, backwardtime = 2000;     private handler durationhandler = new handler();     private seekbar seekbar;     public  string st,satic;      public string url;     private int selectedposition;     private static final string tag_messages = "messages";      public sharedpreferences sharedpreferences;      string filenameee;      public albumnlistadapter(context cxt,arraylist<albumnlistdata>arr) {          this.cxt=cxt;         this.arr=arr;      }      @override     public int getcount() {          return arr.size();     }      @override     public object getitem(int position) {          return position;     }      @override     public long getitemid(int position) {          return position;     }      @override     public view getview(final int position, view convertview, viewgroup parent) {          view v=convertview;         if(v==null)         {             v=view.inflate(cxt, r.layout.songslistitem, null);         }         textview tvaudioname=(textview)v.findviewbyid(r.id.text1);         linearlayout laysong = (linearlayout)v.findviewbyid(r.id.lvsong);         tvaudioname.settext(arr.get(position).strgeneralid);           sharedpreferences = cxt.getsharedpreferences(prefs_name, context.mode_private);         satic ="http://sabakuch.org/public/uploads/tracks/";          laysong.setonclicklistener(new onclicklistener() {          @override         public void onclick(view v) {             // todo auto-generated method stub             filenameee = arr.get(position).strsongfileid;                toast.maketext(cxt, filenameee, toast.length_short).show();              string playsongpath =satic+filenameee;               intent =new intent(cxt,playsong.class);              i.putextra("path", playsongpath);              i.setflags(intent.flag_activity_new_task);              cxt.startactivity(i);          }      });           return v;     } } 

here next activity in playing song.

   protected void oncreate(bundle savedinstancestate) {    super.oncreate(savedinstancestate);      //set layout of activity     setcontentview(r.layout.songsplay);     path =getintent().getextras().getstring("path");     name =getintent().getextras().getstring("name");      mediaplayer = mediaplayer.create(playsong.this, uri.parse(path));     finaltime = mediaplayer.getduration();     //initialize views     initializeviews(); }  public void initializeviews(){        b1 = (imageview) findviewbyid(r.id.backbutton);        b3=(imageview)findviewbyid(r.id.playbutton);       b4=(imageview)findviewbyid(r.id.nextbutton);        if(index==0){           b3.setvisibility(view.visible);          //b2.setvisibility(view.gone);          }else if(index==1){              b3.setvisibility(view.gone);             //b2.setvisibility(view.visible);          }      //mediaplayer = mediaplayer.create(this, uri.parse(path));  //  finaltime = mediaplayer.getduration();        b3.setonclicklistener(new view.onclicklistener() {          @suppresslint("newapi") @override          public void onclick(view v) {                  index=1;                 changeimagebutton();                  mediaplayer.start();                 finaltime = mediaplayer.getduration();            }           });         b1.setonclicklistener(new view.onclicklistener() {          @override          public void onclick(view v) {             int temp = (int)starttime;              if((temp+forwardtime)<=finaltime){                starttime = starttime + forwardtime;                mediaplayer.seekto((int) starttime);                 toast.maketext(getapplicationcontext(),"you have jumped forward 5 seconds",toast.length_short).show();             }             else{                toast.maketext(getapplicationcontext(),"cannot jump forward 5 seconds",toast.length_short).show();             }          }       });        b4.setonclicklistener(new view.onclicklistener() {          @override          public void onclick(view v) {             int temp = (int)starttime;              if((temp-backwardtime)>0){                starttime = starttime - backwardtime;                mediaplayer.seekto((int) starttime);                toast.maketext(getapplicationcontext(),"you have jumped backward 5 seconds",toast.length_short).show();             }             else{                toast.maketext(getapplicationcontext(),"cannot jump backward 5 seconds",toast.length_short).show();             }          }       });    }     protected void changeimagebutton() {         if(index==0){          b3.setvisibility(view.visible);          }else if(index==1){              b3.setvisibility(view.gone);         } }  private runnable updatesongtime = new runnable() {       public void run() {          starttime = mediaplayer.getcurrentposition();           myhandler.postdelayed(this, 100);       }    };      @override     public void onbackpressed ()     {       if (mediaplayer != null)           mediaplayer.stop();       super.onbackpressed();     }     @override    public void onpause ()    {      if (mediaplayer != null)      {          mediaplayer.pause();          mediaplayer.stop();      }      super.onpause();    } 

}

i not having issue till now, when want change song. guess if able change selectedposition in previous adapter class, able next , previous song api. how can that?? please me. in advance.

i have resolved issue, logic behind clicked item in songlist in activity1 , selectedposition. parse selected songlist value in activity2. after got same songlist in activity2 too. using for-loop, compared songlist selectedposition. this, got current value of selected item, set index in musicplayer. when select next , previous song, increase , decrease current index , got item of current index.