OPay Bank Debit API

                            
                                 import com.google.gson.Gson;
                                 import org.apache.commons.codec.binary.Hex;
                                 import javax.crypto.Mac;
                                 import javax.crypto.spec.SecretKeySpec;
                                 import java.io.BufferedReader;
                                 import java.io.InputStreamReader;
                                 import java.io.OutputStream;
                                 import java.net.HttpURLConnection;
                                 import java.net.URL;
                                 import java.nio.charset.StandardCharsets;
                                 import java.util.TreeMap;
                                 import java.util.UUID;

                                 public class BindBankDebitAgreement {

                                     private static final String privateKey = "OPAYPRV1638774******57474";

                                     private static final String endpoint = "https://sandboxapi.opaycheckout.com";

                                     private static final String merchantId = "281821120675251";

                                     public static void main(String[] args) throws Exception {
                                         String addr = endpoint + "/api/v1/international/payment/create";
                                         Gson gson = new Gson();
                                         TreeMap order = new TreeMap<>();
                                         TreeMap amount = new TreeMap<>();
                                         amount.put("currency","EGP");
                                         amount.put("total",1000);
                                         order.put("amount",amount);
                                         TreeMap bankDebit = new TreeMap<>();
                                         bankDebit.put("agreementDuration","2022-02-01");
                                         bankDebit.put("agreementId",UUID.randomUUID().toString());
                                         bankDebit.put("storeCard",true);
                                         order.put("bankDebit",bankDebit);
                                         TreeMap bankcard = new TreeMap<>();
                                         bankcard.put("cardHolderName","DAVID");
                                         bankcard.put("cardNumber","45087********");
                                         bankcard.put("cvv","100");
                                         bankcard.put("enable3DS",true);
                                         bankcard.put("expiryMonth","02");
                                         bankcard.put("expiryYear","26");
                                         order.put("bankcard", bankcard);
                                         order.put("callbackUrl","https://your-callback-url.com");
                                         order.put("country","EG");
                                         order.put("merchantName","test merchant");
                                         order.put("payMethod","CardDebit");
                                         TreeMap product = new TreeMap<>();
                                         product.put("description","description");
                                         product.put("name","name");
                                         order.put("product",product);
                                         order.put("reference",UUID.randomUUID().toString());
                                         order.put("returnUrl","https://your-return-url.com");
                                         TreeMap userInfo = new TreeMap<>();
                                         userInfo.put("userEmail","customer@email.com");
                                         userInfo.put("userId","666666");
                                         userInfo.put("userMobile","201066668888");
                                         userInfo.put("userName","David");
                                         order.put("userInfo",userInfo);

                                         String requestBody = gson.toJson(order);
                                         System.out.println("--request:");
                                         System.out.println(requestBody);
                                         String oPaySignature = hmacSHA512(requestBody, privateKey);
                                         System.out.println("--signature:");
                                         System.out.println(oPaySignature);

                                         URL url = new URL(addr);
                                         HttpURLConnection con = (HttpURLConnection)url.openConnection();
                                         con.setRequestMethod("POST");
                                         con.setRequestProperty("Content-Type", "application/json; utf-8");
                                         con.setRequestProperty("Authorization", "Bearer "+oPaySignature);
                                         con.setRequestProperty("MerchantId", merchantId);
                                         con.setDoOutput(true);
                                         OutputStream os = con.getOutputStream();
                                         byte[] input = requestBody.getBytes(StandardCharsets.UTF_8);
                                         os.write(input, 0, input.length);
                                         BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream(), StandardCharsets.UTF_8));
                                         StringBuilder response = new StringBuilder();
                                         String responseLine = null;
                                         while ((responseLine = br.readLine()) != null) {
                                             response.append(responseLine.trim());
                                         }

                                         System.out.println("--response:");
                                         System.out.println(response.toString());
                                         //close your stream and connection
                                     }

                                     public static String hmacSHA512(final String data, final String secureKey) throws Exception{
                                         byte[] bytesKey = secureKey.getBytes();
                                         final SecretKeySpec secretKey = new SecretKeySpec(bytesKey, "HmacSHA512");
                                         Mac mac = Mac.getInstance("HmacSHA512");
                                         mac.init(secretKey);
                                         final byte[] macData = mac.doFinal(data.getBytes());
                                         byte[] hex = new Hex().encode(macData);
                                         return new String(hex, StandardCharsets.UTF_8);
                                     }
                                 }