HttpurlConnection Post Request body php server?

Question

I have server with a file. php well I want to send post request to the server with my app I'm trying to do that but I always got "" when i try my server on postman i get

{"result": "jfYRsbW17HA3bHtaJdDm", "errorMessage": "error"}

I want my app to see those when i send Post Request here is my code : (why i am getting null)

public class HttpParoonakRequest {


public static String HttpParoonakRequestGetUrl(){


    URL url ;
        HttpURLConnection client = null;
    try {

        url = new URL("myphp");

        client = (HttpURLConnection) url.openConnection();
       client.setRequestMethod("POST");

        client.setRequestProperty("method","get_random_wallpaper");



        client.setDoInput(true);
        client.setDoOutput(true);
        client.connect();
        DataOutputStream wr = new DataOutputStream (
                client.getOutputStream ());

        wr.flush ();
        wr.close ();

        //Get Response
        InputStream is = client.getInputStream();
        BufferedReader rd = new BufferedReader(new InputStreamReader(is));
        String line;
        StringBuffer response = new StringBuffer();

        while((line = rd.readLine()) != null) {
            response.append(line);
            response.append('\n');

        }
        Log.d("hey",response.toString());

        rd.close();

        return response.toString();


    } catch (Exception e) {

        e.printStackTrace();
        return e.getMessage();
    }
    finally {
        if(client != null) // Make sure the connection is not null.
            client.disconnect();
    }



}

and call it this way in another activity:

 thread = new Thread(new Runnable() {


            @Override
            public void run() {
                try {
                    String abcd = HttpParoonakRequest.HttpParoonakRequestGetUrl();
                    System.out.println("Message1 "+ abcd);

                } catch (Exception e) {

                  e.printStackTrace();
                    e.getMessage();
               }

            }
        });
        thread.start();

Answer 1

You pass parameters by wrong way: You should replace client.setRequestProperty("method","get_random_wallpaper") by client.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); and pass your parameter in request body via wr stream like this:

                ...    

                client = (HttpURLConnection) url.openConnection();
                client.setRequestMethod("POST");

                client.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

                client.setDoInput(true);
                client.setDoOutput(true);
                client.connect();
                DataOutputStream wr = new DataOutputStream(
                        client.getOutputStream());

                wr.write("method=get_random_wallpaper".getBytes());

                wr.flush();
                wr.close();
                ...