Trying to get an Access Token from Dwolla restful api

Question

Im having trouble getting an access token for the sandbox environment. Im following this guide for authenticating: OAuth

So when i create my request, following this guide, i get the following response from the api: {"error":"access_denied","error_description":"Invalid application credentials."}

Im using key for mf client ID and secret as my client secret as per the instructions.

Here is the code Im using:

public static void main(String[] args) {
    try {

        URL url = new URL("https://www.dwolla.com/oauth/v2/token");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");

            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    conn.setRequestProperty("client_id", "<Key>");
            conn.setRequestProperty("client_secret", "<Secret>");
            conn.setRequestProperty("grant_type", "client_credentials"); 


            conn.setDoInput(true);
            conn.setDoOutput(true);



            System.out.println("Message:" + conn.getResponseMessage());

            BufferedReader br = new BufferedReader(new InputStreamReader(
            (conn.getInputStream())));

    String output;
    System.out.println("Output from Server .... \n");
    while ((output = br.readLine()) != null) {
        System.out.println(output);
    }

    conn.disconnect();
    } catch (MalformedURLException ex) {
        Logger.getLogger(PaymentTest.class.getName()).log(Level.SEVERE, null, ex);
    } catch (IOException ex) {
        Logger.getLogger(PaymentTest.class.getName()).log(Level.SEVERE, null, ex);
    }

}

Answer 1

I was able to get an access token finally. My problem is first of all the above code uses client_id and client_secret as header params. These need to go in the body of the request.

My second problem is that I used the wrong content type for the message I was sending.

Here is the code that worked for me:

URL url = new URL("https://sandbox.dwolla.com/oauth/v2/token");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");

        conn.setRequestProperty("Content-Type", "application/json");


        conn.setDoInput(true);
        conn.setDoOutput(true);

        String data = "";


    JSONObject jsonObj = new JSONObject();
    jsonObj.put("client_id", "<Your Client ID>");
    jsonObj.put("client_secret", "<Your Client Secret>");
    jsonObj.put("grant_type", "client_credentials");

    data = jsonObj.toString();

    System.out.println("data = " + data);



    byte[] outputInBytes = data.getBytes("UTF-8");
    OutputStream os = conn.getOutputStream();
    os.write( outputInBytes );    
    os.close();


    System.out.println("Message:" + conn.getResponseMessage());


    BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())));

    String output;
    System.out.println("Output from Server .... \n");
    while ((output = br.readLine()) != null) {
        System.out.println(output);
    }

    conn.disconnect();