Java – Use Android Studio’s GDAX REST API requests

Hello, I’m trying to make a REST api call from GDAX using android studio, I’m new to REST calling, so it’s hard for me to make this call

I believe this is the api endpoint
Link
IT SAYS IT NEEDS THE CB-ACCESS-KEY header

This is a list of all required headers

All REST requests must contain the following header:

–

CB-ACCESS-KEY AS THE API KEY FOR THE STRING.

–

CB-ACCESS-SIGN base64 encoded signature (see Message signature).

–

CB-ACCESS-TIMESTAMP The timestamp of the request.

–

CB-ACCESS-PASSPHRASE The password you specified when you created the api key.

– All request bodies should have the content type application/json and be valid JSON.

Full documentation link click here

This is the code I tried to use but was unlucky

private class InfoTask extends AsyncTask<String, String, String> {
    @Override
    protected String doInBackground(String... urls) {
        System.out.println("oooooooooooooooooooook             working2");
        HttpURLConnection conn = null;
        BufferedReader reader = null;

try{
            String query = urls[0];
            URL url = new URL(endpoint+query);
            System.out.println(url);
            conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(10000 /* milliseconds */);
            conn.setConnectTimeout(15000 /* milliseconds */);
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setRequestMethod("GET");

conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestProperty("CB-ACCESS-KEY", key);
             conn.setRequestProperty("CB-ACCESS-SIGN", generate(params[0], "GET", "", String.valueOf(System.currentTimeMillis())));
            String timestamp = String.valueOf(System.currentTimeMillis());
            conn.setRequestProperty("CB-ACCESS-TIMESTAMP", timestamp);
            conn.setRequestProperty("CB-ACCESS-PASSPHRASE", passprase);

Writer writer = new OutputStreamWriter(conn.getOutputStream());
            writer.write(query);
            writer.flush();
            writer.close();

conn.connect();
            InputStream is = conn.getInputStream();
            reader = new BufferedReader(new InputStreamReader(is));
            StringBuffer sb = new StringBuffer();
            String line = "";
            while((line = reader.readLine()) != null){
                sb.append(line);
            }
            return sb.toString();
        }catch (MalformedURLException e){
            e.printStackTrace();
        } catch (IOException e){
            e.printStackTrace();
        }
        return null;
    }
    protected void onPostExecute(String result){
        TextView t = findViewById(R.id.t);
        t.setText(result);
    }

}

I call this task in my onCreate

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    new InfoTask().execute("accounts");
}

I’M NOT SURE WHAT PARAMETERS TO USE FOR CB-ACCESS-SIGN AND DON’T KNOW WHERE TO ADD MY API PASSWORD, PLEASE HELP

As described in the API

The CB-ACCESS-SIGN header is generated by creating a sha256 HMAC using
the base64-decoded secret key on the prehash string timestamp + method
+ requestPath + body (where + represents string concatenation) and base64-encode the output. The timestamp value is the same as the
CB-ACCESS-TIMESTAMP header

You need to do something :

public String generate(String requestPath, String method, String body, String timestamp) {
        try {
            String prehash = timestamp + method.toUpperCase() + requestPath + body;
            byte[] secretDecoded = Base64.getDecoder().decode(secretKey);
            SecretKeySpec keyspec = new SecretKeySpec(secretDecoded, GdaxConstants.SHARED_MAC.getAlgorithm());
            Mac sha256 = (Mac) GdaxConstants.SHARED_MAC.clone();
            sha256.init(keyspec);
            return Base64.getEncoder().encodeToString(sha256.doFinal(prehash.getBytes()));
        } catch (CloneNotSupportedException | InvalidKeyException e) {
            e.printStackTrace();
            throw new RuntimeErrorException(new Error("Cannot set up authentication headers."));
        }
    }

Another approach is to use gdax-java, which is gdax’s java client library