How to fix download from server bug in Android -

i want download file server , use code:

class downloadfilefromurl2 extends asynctask<string, string, string> {          /**          * before starting background thread          * show progress bar dialog          */         @override         protected void onpreexecute() {             super.onpreexecute();             showdialog(progress_bar_type);         }          /**          * downloading file in background thread          */         @override         protected string doinbackground(string... f_url) {             int count;             try {                 file sdcardroot = environment.getexternalstoragedirectory();                 file directory = new file(sdcardroot, "/raz/");                 url url = new url(f_url[0]);                 urlconnection conection = url.openconnection();                 conection.connect();                 // useful can show tipical 0-100% progress bar                 int lenghtoffile = conection.getcontentlength();                  // download file                 inputstream input = new bufferedinputstream(url.openstream(), 8192);                  // output stream                 outputstream output = new fileoutputstream("/sdcard/downloadedfile.pdf");                  byte data[] = new byte[1024];                  long total = 0;                  while ((count = input.read(data)) != -1) {                     total += count;                     // publishing progress....                     // after onprogressupdate called                     publishprogress("" + (int) ((total * 100) / lenghtoffile));                      // writing data file                     output.write(data, 0, count);                 }                  // flushing output                 output.flush();                  // closing streams                 output.close();                 input.close();              } catch (exception e) {                 log.e("error: ", e.getmessage());             }              return null;         }          /**          * updating progress bar          */         protected void onprogressupdate(string... progress) {             // setting progress percentage             pdialog.setprogress(integer.parseint(progress[0]));         }          /**          * after completing background task          * dismiss progress dialog          **/         @override         protected void onpostexecute(string file_url) {             // dismiss dialog after file downloaded             dismissdialog(progress_bar_type);          }     } 

but in codes can't set custom path download files, example can't set application name folder.

for write code instance of outputstrim :

outputstream output = new fileoutputstream(new file(directory, "pdf_dl.pdf")); 

but when add code, not download file server!

how can fix this?