Trying to POST data from my android application to a php file on a server but data is always null. Why

Question

The post variable is never being set and for now, all I'm trying to do is set that variable but it's always null

All my credentials are correct and I am accessing the the php file but just unable to post any data at all. Could this be a problem on my server?

This is my java code:

try {

            URL url = new URL("http://ggh.com/ghh.php");
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestProperty("Accept", "application/json");
            conn.setRequestMethod("POST");
            conn.setReadTimeout(15 * 1000);
            conn.setConnectTimeout(15 * 1000);
            conn.setDoOutput(true);
            conn.setDoInput(true);

            OutputStream os = conn.getOutputStream();

            BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));

            Uri.Builder builder = new Uri.Builder()
                    .appendQueryParameter("password", password)
                    .appendQueryParameter("username", username);
            String query = builder.build().getEncodedQuery();

            bufferedWriter.write(query);

            bufferedWriter.flush();
            bufferedWriter.close();
            os.close();

            conn.connect();

            InputStream inputStream = conn.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
            String line = "";

            while ((line = bufferedReader.readLine()) != null) {
                response += line;
            }
            try {
                objmain = new JSONObject(response);
                jsonArray = objmain.getJSONArray("apps");
                for (int i = 0; i < jsonArray.length(); i++) {

                    obj = jsonArray.getJSONObject(i);
                    pass = (obj.getString("password"));
                    pass_hash = (obj.getString("password_hash"));
                    first_name = (obj.getString("first_name"));
                    last_name = (obj.getString("last_name"));
                    email_personal = (obj.getString("email_personal"));
                    phone_personal = (obj.getString("phone_personal"));
                    linkedin = (obj.getString("linkedin"));
                    company_name = (obj.getString("company_name"));
                    job_title = (obj.getString("job_title"));
                    phone_professional = (obj.getString("phone_professional"));
                    email_professional = (obj.getString("email_professional"));
                    address = (obj.getString("address"));
                    database = username + "_db";

                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            bufferedReader.close();
            inputStream.close();
            conn.disconnect();

        } catch (IOException e) {
            e.printStackTrace();
        }

My php code:

<?php

$servername = "sad.com";
$username = "ad";
$password = "adad";

// Create connection
$conn = new mysqli($servername, $username, $password);

// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
} 

mysqli_select_db($conn,"connkt");

function hashPassword($password, $salt) {
$hash_password = hash("SHA512", base64_encode(str_rot13(hash("SHA512",    str_rot13($salt . $password)))));
return $hash_password;
}


$user = $_POST['username'];  

$pass = $_POST['password'];

$hashed_password = hashPassword('someday', $pass);

$response["apps"] = array();

$result = mysqli_query($conn, "Select * FROM `users` WHERE username='$user'   LIMIT 1");

while($row=mysqli_fetch_array($result))
{
$apps = array();

  $apps["password"] = $row["password"];
  $apps["first_name"] = $row["first_name"];
  $apps["last_name"] = $row["last_name"];
  $apps["email_personal"] = $row["email_personal"];
  $apps["facebook"] = $row["facebook"];
  $apps["phone_personal"] = $row["phone_personal"];
  $apps["linkedin"] = $row["linkedin"];
  $apps["company_name"] = $row["company"];
  $apps["job_title"] = $row["title"];
  $apps["phone_professional"] = $row["phone_professional"];
  $apps["email_professional"] = $row["email_professional"];
  $apps["address"] = $row["address"];
  $apps["password_hash"] = $hashed_password;

  array_push($response["apps"], $apps);
}
print(json_encode($user));

Answer 1

I would suggest using Volley to send data to the server :

http://www.androidhive.info/2014/05/android-working-with-volley-library-1/