java - How to use android-async-http library -

i trying use android-async-http library asynchronous file upload server. callback inside method call upload. however, error when trying call method asynctask class. can spot getting error? here upload method:

public void upload(string title, string genre, string description, string songuri, int accountid) {      file song = new file(songuri);      try {         string url = uri.parse(getresources().getstring(r.string.audio_upload_url))                 .buildupon()                 .appendqueryparameter("title", title)                 .appendqueryparameter("tags", genre)                 .appendqueryparameter("description", description)                 .appendqueryparameter("accountid", string.valueof(accountid))                 .build().tostring();          asynchttpresponsehandler httpresponsehandler = createhttpresponsehandler();          requestparams params = new requestparams();         // path retrieved library or camera         //string imagefilepath = "/storage/sdcard/dcim/camera/img.jpg";         //params.put("data", new file(imagefilepath));          params.put("song", song);          asynchttpclient client = new asynchttpclient();         client.post(url, params, httpresponsehandler);     } catch (ioexception e) {         e.printstacktrace();     }  } 

and here how initialize asynchttpresponsehandler class.

 public asynchttpresponsehandler createhttpresponsehandler() {     asynchttpresponsehandler handler = new asynchttpresponsehandler() {         @override         public void onstart() {             super.onstart();         }          @override         public void onprogress(int position, int length) {             super.onprogress(position, length);              // progressbar.setprogress(position);             //progressbar.setmax(length); }           @override         public void onfinish() {             super.onfinish();         }          @override         public void onsuccess(int i, header[] headers, byte[] bytes) {          }          @override         public void onfailure(int i, header[] headers, byte[] bytes, throwable throwable) {          }      };      return handler; } 

and in asynctask class, how calling upload method.

@override     protected uploadfragment doinbackground(uploadfragment... params) {         string title = titleet.gettext().tostring();         string description = descriptionet.gettext().tostring();          int user_id;         userdetails = sessionmanager.getuserdetails();         user user = userdetails.get(0);         user_id = user.getuserid();          upload(title, "genre", description, songpath, user_id);         return null;     } 

i error in last line of onpreexecute method of asynctask class because of leaked window, implies getting error when executing doinbackground() method.

use volley library network communication referred google . in android-async-http-library can't cancel particular request possible volley.