android - Showing ProgressBar on parsing and downloading json result -

in app hitting service can have no result n number of results(basically barcodes). of using default circular progressbar when json parsed , result being saved in local db(using sqlite). if json has large number of data takes 30-45 min parse , simultaneously saving data in db, makes interface unresponsive period of time , makes user think app has broken/hanged. problem want show progressbar percentage stating how data parsed , saved user know app still working , not dead. took link couldn't find how achieve. here's asynctask,

class backgroundtasks extends asynctask<string, string, void> {     private string operation, itemref;     private arraylist<model_barcodedetail> changedbarcodelist, barcodelist;     private arraylist<string> changereflist;     string page;      public backgroundtasks(string operation, string itemref, string page) {         this.operation = operation;         this.itemref = itemref;         this.page = page;     }      @override     protected void onpreexecute() {         // todo auto-generated method stub         super.onpreexecute();         if (dialog == null) {             dialog = progressdialog.show(mactivity, null,                     "please wait ...", true);          }      }      @override     protected void doinbackground(string... params) {         // todo auto-generated method stub         try{         if (!connection.havenetworkconnection()) {             dialog.dismiss();              connection.showtoast(screensize,  "no internet connection.");             return null;         }            if (operation.equalsignorecase("downloadchangeitemref")) {             changereflist = downloadchangeitemref(params[1]);             if (changereflist != null && !changereflist.isempty()) {                 reflist1.addall(changereflist);             }           }         if ((changereflist != null && changereflist.size() >0)) {             setupdatedbarcodes(changedbarcodelist);             }          }         } catch (exception e) {             e.printstacktrace();         }         return null;     }      @suppresslint("simpledateformat")     @override     protected void onpostexecute(void result) {          super.onpostexecute(result);     }  }      arraylist<string> downloadchangeitemref(string api_token) {     arraylist<string> changedreflist = null;     httpclient httpclient = new defaulthttpclient();     httppost postrequest = new httppost(thoth_url + "/" + todaysdate             + "?&return=json");      string url = thoth_url + "/" + todaysdate + "?&return=json";     string result = "";     try {         changedreflist = new arraylist<string>();         responsehandler<string> responsehandler = new basicresponsehandler();         result = httpclient.execute(postrequest, responsehandler);         jsonobject jsonobj = new jsonobject(result);         jsonarray jsonarray = jsonobj.getjsonarray("changes");         if (jsonarray.length() == 0) {             return null;         }         (int = 0; < jsonarray.length(); i++) {             jsonobject obj = jsonarray.getjsonobject(i);             changedreflist.add(obj.getstring("ref"));         }     } catch (illegalstateexception e) {         // todo auto-generated catch block         // when there no thoth url         log.i("inclient: ", e.getmessage());          return null;     } catch (exception e) {         // when there no itemref          return null;     }     return changedreflist; }   private boolean setupdatedbarcodes(             final arraylist<model_barcodedetail> changedbarcodelist2) {          try {                     barcodedatabase barcodedatabase = new barcodedatabase(mactivity);                     barcodedatabase.open();                     (model_barcodedetail model : changedbarcodelist2) {                         barcodedatabase.updateentry(model, userid);                     }                      n++;                     barcodedatabase.close();                     if (reflist1.equals(reflist)) {                          if (dialog != null) {                             dialog.dismiss();                         }                          connection.showtoast(screensize,  "barcodes updated successfully");                     }          } catch (exception e) {             log.i("exception caught in: ", "setdownloadedbarcodes method");             e.printstacktrace();             return false;         }         return true;      }