Cache-Control : no-cache

I tried to build an app in android studio which does json parsing from a URL server with ports (example: http://xxx.xxx.xxx.xxx:xxxx). So I found 3 methods such as asynctask, volley and okhttp. But the problem is everytime I parse it with these methods, the same exception always occurred.

java.net.ProtocalException: Unexpected status line: HTTP/1.1 Cache-Control:no-cache

Here is my code

 class GetJSON extends AsyncTask<Void, Void, String> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(MainActivity.this);
            pDialog.setMessage("Please Wait");
            pDialog.setCancelable(false);
            pDialog.show();

            viewId = (TextView) findViewById(R.id.ID) ;
        }

        @Override
        protected String doInBackground(Void... voids) {
            try {
                URL url = new URL(urlWebService);
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                StringBuilder sb = new StringBuilder();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
                String json;

                while ((json = bufferedReader.readLine()) != null) {
                    sb.append(json + "n");
                }

                JSONObject data = new JSONObject(sb.toString().trim());

                return sb.toString().trim();

            } catch (final Exception e) {
                e.printStackTrace();
                resp = e.getMessage();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast toast = Toast.makeText(getApplicationContext(), resp, Toast.LENGTH_LONG);
                        toast.setGravity(Gravity.CENTER_VERTICAL, Gravity.CENTER_HORIZONTAL, 0);
                        toast.show();

                    }
                });
            }
            return null;
        }

        @Override
        protected void onPostExecute(String rawData) {
            super.onPostExecute(rawData);
            if (pDialog.isShowing())
                pDialog.dismiss();

            viewId.setText(rawData);
        }


    }

So is there any method to do this parsing? Or any solution?

Answer

Okay so apparently the problem was not with the code I am using, but the server API’s responses. The server didn’t response when I hit the API but now it’s working perfectly fine!