Android Volley - 发布请求 - 不向 php 发送参数

Question

I was trying to make a POST request with parameter through Volley. It is working totally fine to response query result from database IN MY ANDROID APP but when i show the values of this query in php the then show error undefined index variable "uploaded_by".

JAVA CODE:

 StringRequest stringRequest = new StringRequest(Request.Method.POST, REGISTER_URL,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        Toast.makeText(MainActivity.this,response,Toast.LENGTH_LONG).show();
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Toast.makeText(MainActivity.this,error.toString(),Toast.LENGTH_LONG).show();
                    }
                }){
            @Override
            protected Map<String,String> getParams(){
                Map<String,String> params = new HashMap<String, String>();
                params.put(KEY_USERNAME,username);
                params.put(KEY_PASSWORD,password);
                params.put(KEY_EMAIL, email);
                return params;
            }

        };

        RequestQueue requestQueue = Volley.newRequestQueue(this);
        requestQueue.add(stringRequest);
    }

---

1. Heading

   #

PHP CODE:

<?php
//This script is designed by Android-Examples.com
//Define your host here.
$servername = "localhost";
//Define your database username here.
$username = "root";
//Define your database password here.
$password = "";
//Define your database name here.
$dbname = "u288012116_and";

$connection = new mysqli($servername,$username,$password,$dbname) ;

// Innitialize Variable
if($_SERVER['REQUEST_METHOD'] == 'POST')
 {

 $StudentData = $_POST['uploaded_by'];




          //fetch table rows from mysql db
$sql = "SELECT image_title,image_url FROM  `imagelistviewtable` WHERE  `uploaded_by` = '". $StudentData . "'";


$result = mysqli_query($connection, $sql) or die("Error in Selecting " . mysqli_error($connection));

    //create an array
$emparray = array();
while($row = mysqli_fetch_assoc($result))
    {
        $emparray[] = $row;
    }


$json = json_encode($emparray);
if ($json === false) {
    // Avoid echo of empty string (which is invalid JSON), and
    // JSONify the error message instead:
    $json = json_encode(array("jsonError", json_last_error_msg()));
    if ($json === false) {
        // This should not happen, but we go all the way now:
        $json = '{"jsonError": "unknown"}';
    }
    // Set HTTP response status code to: 500 - Internal Server Error
    http_response_code(500);
}

echo $json;
//close the db connection
    mysqli_close($connection);
 }

    ?>

Answer 1

 public static void getServerData(final Context cntx) {
        RequestQueue queue = Volley.newRequestQueue(cntx);


        JsonObjectRequest jsObjRequest = new JsonObjectRequest(
                Request.Method.POST, "Url", json_object,
                new Response.Listener<JSONObject>() {

                    @Override
                    public void onResponse(JSONObject response) {

                         // Your response

                    }
                }, new Response.ErrorListener() {

                    @Override
                    public void onErrorResponse(VolleyError error) {
                        // TODO Auto-generated method stub

                    }

                }) {
            @Override
            public Map<String, String> getHeaders() throws AuthFailureError {

                // Your header parameter if you have otherwise this is optional

                return headers;
            }
        };
   queue.add(jsObjRequest);
}

Answer 2

I'm a bit late to answer this, but I think it may help someone facing same problem. I search through all similar questions on SO, relating to PHP and Volley api but I didn't find any satisfying answer.

The problem is that you are sending data from the Volley library as content type

application/json

but your PHP script is expecting POST data as content type

application/x-www-form-urlencoded

In your PHP script, do this:

$_POST = json_decode(file_get_contents('php://input'), true);

if ( !empty($_POST['uploaded_by']) ) {

    $StudentData = $_POST['uploaded_by'];
    echo $StudentData;
}

Now if you check for

if( isset($_POST['uploaded_by']) ){

    echo "something";
}

it should work now