在php中获取null值

Question

我正在使用POST从android到php文件传递url中的一些值我得到空值。

请帮忙！

我的其他PHP代码运行良好，但唯一的问题是它无法从网址中提取值。

我的PHP代码：

    $b = $_POST['bal']; 
    $balance_tobe_added = intval($b);
    $h1 = $_POST['hotcode'];
    $hotcode = intval($h1);
    $date = $_POST['date'];
    $time = $_POST['time'];
    $city = $_POST['city'];

    echo $b.$h.$date.$time.$city;

我的android代码是：

 private void updateDB(String balance, String hotcode, String date, String time, String city) {
    class DBupdate extends AsyncTask<String, Void, String> {
        @Override
        protected void onCancelled() {
            super.onCancelled();
            Toast.makeText(MainActivity.this,"error",Toast.LENGTH_SHORT).show();
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
             Toast.makeText(MainActivity.this,s,Toast.LENGTH_SHORT).show();

        }



        @Override
        protected String doInBackground(String... strings) {
            String res = "failed";
            try {
                URL url = new URL("http://www.mrhot.in/Customer/test/test.php");
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                con.setRequestMethod("POST");
                con.setDoInput(true);
                con.setDoOutput(true);
                OutputStream os = con.getOutputStream();
                BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
                StringBuilder input = new StringBuilder();
                input.append(URLEncoder.encode("bal", "UTF-8"));
                input.append(URLEncoder.encode("=", "UTF-8"));
                input.append(URLEncoder.encode(strings[0], "UTF-8"));
                input.append(URLEncoder.encode("&", "UTF-8"));

                input.append(URLEncoder.encode("hotcode", "UTF-8"));
                input.append(URLEncoder.encode("=", "UTF-8"));
                input.append(URLEncoder.encode(strings[1], "UTF-8"));
                input.append(URLEncoder.encode("&", "UTF-8"));

                input.append(URLEncoder.encode("date", "UTF-8"));
                input.append(URLEncoder.encode("=", "UTF-8"));
                input.append(URLEncoder.encode(strings[2], "UTF-8"));
                input.append(URLEncoder.encode("&", "UTF-8"));

                input.append(URLEncoder.encode("time", "UTF-8"));
                input.append(URLEncoder.encode("=", "UTF-8"));
                input.append(URLEncoder.encode(strings[3], "UTF-8"));
                input.append(URLEncoder.encode("&", "UTF-8"));

                input.append(URLEncoder.encode("city", "UTF-8"));
                input.append(URLEncoder.encode("=", "UTF-8"));
                input.append(URLEncoder.encode(strings[4], "UTF-8"));

                String i = input.toString();
                writer.write(i);
                writer.flush();
                writer.close();
                os.close();

                int response = con.getResponseCode();
                if(response == HttpURLConnection.HTTP_OK){
                    BufferedReader r = new BufferedReader(new InputStreamReader(con.getInputStream()));
                    res = r.readLine();

                }
            } catch (Exception e) {
                e.printStackTrace();
                res =  "error";
            }
            return res;
        }
    }
    DBupdate obj = new DBupdate();
    obj.execute(balance, hotcode, date, time, city);
}