private static String receiveFromBackEnd(String url, String json) throws IOException, JSONException {
StringBuilder str = new StringBuilder();
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
httppost.addHeader(new BasicHeader("Content-Type",
"application/json"));
httppost.setEntity(new StringEntity(json));
HttpResponse response = httpclient.execute(httppost);
BufferedReader reader = new BufferedReader(new InputStreamReader(
response.getEntity().getContent()));
String line;
while ((line = reader.readLine()) != null) {
str.append(line);
}
return str.toString();
}