android - postexecute in asynctask is not executing -

@override protected string doinbackground(string... params) {     // todo auto-generated method stub     url3="http://www.digitalmarketingbox.com/webtool/boxdata/"+mainactivity.abc+"/updates.zip";      try {         httpurlconnection.setfollowredirects(false);         // note : may need         //        httpurlconnection.setinstancefollowredirects(false)         httpurlconnection con =(httpurlconnection) new url(params[0]).openconnection();         con.setrequestmethod("head");         x=con.getresponsecode() == httpurlconnection.http_ok;       }       catch (exception e) {          e.printstacktrace();          x=false;       }       try {         httpurlconnection.setfollowredirects(false);         // note : may need         //        httpurlconnection.setinstancefollowredirects(false)         httpurlconnection con =(httpurlconnection) new url(url3).openconnection();         con.setrequestmethod("head");         xc=con.getresponsecode() == httpurlconnection.http_ok;       }       catch (exception e) {          e.printstacktrace();          xc=false;       }      //x=exists(params[0]);     //xc=exists(url3);     valve=string.valueof(x);      if(valve.equals("true"))     {      finalurl=url+ mainactivity.abc + "/resources.zip";     filename="resources.zip";     mainactivity.fl1=filename;     log.i("filename",filename);     }      else if(xc==true)      {     finalurl=url+ mainactivity.abc + "/updates.zip";         filename="updates.zip";     mainactivity.fl1=filename;     log.i("filename",filename);     }      else      {     try     {         httpclient client = new defaulthttpclient();            log.i("url checking update",url1);          httppost post = new httppost(url1);           list<namevaluepair> parameters = new arraylist<namevaluepair>();          parameters.add(new basicnamevaluepair("reqtype", "resendcontent"));          parameters.add(new basicnamevaluepair("menuboxid",mainactivity.abc));          parameters.add(new basicnamevaluepair("updatetoken", "dmb20101512"));          urlencodedformentity ent;          ent = new urlencodedformentity(parameters,http.utf_8);          post.setentity(ent);          httpresponse responsepost = client.execute(post);            httpentity resentity = responsepost.getentity();           finalurl=url+ mainactivity.abc + "/updates.zip";            filename="updates.zip";         mainactivity.fl1=filename;         log.i("filename",filename);         log.i("url",finalurl);       }      catch (final ioexception e) {                   e.printstacktrace();         }     try {         thread.sleep(2000);     } catch (interruptedexception e) {         // todo auto-generated catch block         e.printstacktrace();     }     finalurl=url+ mainactivity.abc + "/updates.zip";         filename="updates.zip";     mainactivity.fl1=filename;     }      try{         url url = new url(finalurl);         httpurlconnection urlconnection = (httpurlconnection) url.openconnection();         urlconnection.setrequestmethod("get");         urlconnection.setdooutput(true);         urlconnection.connect();                     //file sdcardroot = environment.getexternalstoragedirectory();         filedestination=environment.getexternalstoragedirectory() +"/" + filename;         //file file = new file(sdcardroot,filename);         file file = new file(filedestination);         fileoutputstream fileoutput = new fileoutputstream(file);         inputstream inputstream = urlconnection.getinputstream();         totalsize = urlconnection.getcontentlength();         log.i("size",string.valueof(totalsize));         byte[] buffer = new byte[1024];         int bufferlength = 0;         while ( (bufferlength = inputstream.read(buffer)) > 0 ) {             fileoutput.write(buffer, 0, bufferlength);             downloadedsize += bufferlength;              }         //close output stream when complete //         fileoutput.close();         }         catch (final ioexception e) {                    e.printstacktrace();         }         log.i("download info","download complete");         try {             thread.sleep(2000);         } catch (interruptedexception e) {             // todo auto-generated catch block             e.printstacktrace();         }          string source = environment.getexternalstoragedirectory() + "/" + filename;         log.i("download destination",source);         string destination =environment.getexternalstoragedirectory()+ "/";           log.i("extract destination",destination);         try {             zipfile zipfile = new zipfile(source);               zipfile.extractall(destination);           } catch (zipexception e) {             e.printstacktrace();          }          try         {          httpclient client1 = new defaulthttpclient();              log.i("url is",url1);                httppost post1 = new httppost(url1);              list<namevaluepair> parameters1 = new arraylist<namevaluepair>();             parameters1.add(new basicnamevaluepair("reqtype", "completeupdate"));             parameters1.add(new basicnamevaluepair("menuboxid",mainactivity.abc));             parameters1.add(new basicnamevaluepair("updatetoken", "dmb20101512"));             urlencodedformentity ent1 = new urlencodedformentity(parameters1,http.utf_8);             post1.setentity(ent1);                }           catch (ioexception e) {             // todo auto-generated catch block             e.printstacktrace();         }    return foo; }  @override protected void onpostexecute(string result) {     // todo auto-generated method stu super.onpostexecute(result); //result=bn; /*if(!result.isempty()) { calendar c = calendar.getinstance();  int seconds = c.get(calendar.second); log.i("asynctask finish time",string.valueof(seconds)); }*/ 

}

i using asynctask class in activity task , checking via getstatus method has finished or not ,but never finished above code of asynctask class , postexecute not working can expalin me why?

i have experienced same problem. happens when main ui thread goes sleep. try use timer in ui thread keep awake.