Android App Crashes if no internet during server connection -

i calling url fetch data , insert in database. have provided no internet check. if open app without internet connection, works fins, pop comes.. if connect url when have internet , internet goes in middle process, app crashes, how fix it?

my code:

public class dopostpen extends asynctask<string, void, boolean> implements oncancellistener {     @suppresswarnings("deprecation")     @override     protected boolean doinbackground(string... arg0) {          try {              httpclient client = new defaulthttpclient();             httpget request = new httpget("http://testapi.pharmeazy.in/api/medieazy/getallinvoices");              request.addheader("authorization", " basic ndlyawnva2pvawqwm2ptzglrawres09qzgzpamrmnzy0dda4nwp6mzcyohdzmkpjs1m4mta0c2nvctj1otrkazphd0vemzi3mka4wwfzzeu3mji3iubeiypvsfmq");             request.setheader(http.content_type, "application/json");             system.out.println("priinting");              httpresponse response = null;             try {                 response = client.execute(request);                  log.d("response of request", response.tostring());             } catch (clientprotocolexception e) {                 // todo auto-generated catch block                 e.printstacktrace();             } catch (ioexception e) {                 // todo auto-generated catch block                 e.printstacktrace();             }              inputstream inputstream = response.getentity().getcontent();             string result = utils.convertinputstreamtostring(inputstream);               system.out.println("server response :" + result + "\n" + inputstream);               try {                  ja=new jsonarray(result);                 } catch (exception e) {                 // todo auto-generated catch block                 e.printstacktrace();              }         }         catch (exception e) {             log.e("clientserverdemo", "error:", e);              toasttext2 = "connection error !";         }          return true;     }      protected void onpreexecute() {          //display progress dialog          mprogresshud2 = progresshud.show(med.this,"getting rejected orders", true,false,this);      }      @override     protected void onpostexecute(boolean valid) {         mprogresshud2.dismiss();         // if server response successful         for(int i=0;i<ja.length();i++){             try {             jo=ja.getjsonobject(i);                db.insertlabel(jo.get("id").tostring(), jo.get("customerid").tostring(), jo.get("pharmacyid").tostring(),                      jo.get("deliveryaddress").tostring(), jo.get("deliveryname").tostring(),                        jo.get("orderstatus").tostring(),jo.get("prescriptionattached").tostring(),jo.get("discount").tostring());                  }            catch (jsonexception e) {             // todo auto-generated catch block             e.printstacktrace();         }         }        new dopost3().execute();      } 

please help

why don't go httpurlconection

  @override         protected string doinbackground(string... params) {               string finalresult = null;             url url = null;             httpsurlconnection urlconnection = null;             try {                               url=new url(url);                 urlconnection = (httpsurlconnection) url.openconnection();                 urlconnection.setdooutput(true);                   urlconnection.setdoinput(true);                     urlconnection.setrequestmethod("post");                   urlconnection.setusecaches(false);                   urlconnection.setconnecttimeout(5000);                   urlconnection.setreadtimeout(5000);                   urlconnection.setrequestproperty("content-type","application/json");                  urlconnection.connect();                     outputstreamwriter out = new   outputstreamwriter(urlconnection.getoutputstream());                 out.write(jsonobjsend.tostring());                 out.close();                  starttime = system.currenttimemillis();                  try {                     mresponsecode = urlconnection.getresponsecode();                     totaltime = system.currenttimemillis() - starttime;                     log.e("http post response code:", ""                             + mresponsecode);                 } catch (sslpeerunverifiedexception e) {                      log.e("exception", log.getstacktracestring(e));                 } catch (ioexception e) {                      log.e("exception", log.getstacktracestring(e));                     log.e("http post response code(2):", ""                             + mresponsecode);                 } } 

check before calling asynctask

 if(util.havenetworkconnection(this))         {   httppostdata req=new httppostdata(url, createjsonobject(),this) ;      req.execute();                  }