Make a Withdrawal via REST API (Java)

You can use our APIs to perform cash withdrawals.

This tutorial presents a simple approach to integrating the MOALA APIs to perform a cash withdrawal.

Prerequisites

Before starting, make sure you have the following:

• An account on the MOALA portal with the necessary permissions to make withdrawals. You can create a MOALA account by following the steps here: Get API Keys
• A development environment with Java installed
• The Apache HttpClient library to make HTTP requests

1. Authentication

The MOALA API requires three headers for authentication and transaction security:

• LP-ACCESS-KEY: your MOALA API access key (obtained from the MOALA portal)
• LP-ACCESS-TIMESTAMP: the timestamp of the request in seconds
• LP-ACCESS-SIGN: a signature generated using the secret key and LP-ACCESS-KEY

The LP-ACCESS-SIGN signature is generated using the HMAC-SHA256 algorithm on a concatenation of the key, timestamp, and request body.

2. Perform the Withdrawal

We will now perform a cash withdrawal operation using MOALA's REST APIs.

Withdrawal Endpoint

To make a withdrawal, use the following endpoint, with the serviceCode corresponding to the operator you want to use:

POST https://api.moala.africa/v1/api/transaction/payment

info

The valid serviceCode values for this endpoint are:

• CASHOUT_MTN_CM: Cashout MTN Cameroon
• CASHOUT_ORANGE_CM: Cashout Orange Cameroon
• CASHOUT_AIRTEL_GA: Cashout Airtel Gabon
• CASHOUT_MOOV_GA: Cashout Moov Gabon
• PAIEMENTMARCHAND_MTN_CM: Merchant Payment MTN Cameroon
• PAIEMENTMARCHAND_ORANGE_CM: Merchant Payment Orange Cameroon
• PAIEMENTMARCHAND_AIRTEL_GA: Merchant Payment Airtel Gabon
• PAIEMENTMARCHAND_MOOV_GA: Merchant Payment Moov Gabon

Request Body

Below are the required fields in the request body:

Field	Type	Description
transactionType	string	Type of transaction to perform (fixed value: deposit)
amount	float	Amount to withdraw
serviceCode	string	Code of the service to use (see list above)
phoneNumber	string	Phone number from which to make the withdrawal
partnerId	string	Identifier of the partner initiating the withdrawal

Generating the Signature

We will now write a function to calculate the signature for each request sent to the server.

// Generate request signature
import org.apache.commons.codec.digest.HmacUtils;

public class Utils {
    public static String generateSignature(String secretKey, String timestamp, String method, String endpoint, String payload) throws Exception {
        String message = timestamp + method + endpoint + payload;
        return HmacUtils.hmacSha256Hex(secretKey, message);
    }
}

Sending the Withdrawal Request

Now we build and send the withdrawal request.

import Utils;

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import com.google.gson.Gson;

import java.time.Instant;
import java.util.HashMap;
import java.util.Map;

public class Withdrawal {
    private static final String API_KEY = "votre_api_key";
    private static final String SECRET_KEY = "votre_secret_key";
    private static final String API_BASE_URL = "https://api.moala.africa";

    public static void makeWithdrawal(Float amount, String serviceCode, String phoneNumber, String partnerId) {
        try (CloseableHttpClient client = HttpClients.createDefault()) {
            String endpoint = "/v1/api/transaction/payment";
            String url = API_BASE_URL + endpoint;
            long timestamp = Instant.now().getEpochSecond();

            Map<String, Object> body = new HashMap<>();
            body.put("amount", amount);
            body.put("transactionType", "withdrawal");
            body.put("serviceCode", serviceCode);
            body.put("phoneNumber", phoneNumber);
            body.put("partnerId", partnerId);
            String payload = new Gson().toJson(body);

            String method = "POST";
            String signature = Utils.generateSignature(SECRET_KEY, String.valueOf(timestamp), method, endpoint, payload);

            HttpPost req = new HttpPost(url);
            req.setHeader("LP-ACCESS-KEY", API_KEY);
            req.setHeader("LP-ACCESS-TIMESTAMP", String.valueOf(timestamp));
            req.setHeader("LP-ACCESS-SIGN", signature);
            req.setHeader("Content-Type", "application/json");
            req.setEntity(new StringEntity(payload));

            CloseableHttpResponse response = client.execute(req);
            System.out.println(EntityUtils.toString(response.getEntity()));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

warning

The partnerId field must be unique for each transaction, otherwise the request will fail.

3. Check Operation Status

After sending the withdrawal request, you can verify the status by making another API call.

Status Check Endpoint

Use the endpoint below to check the status of the previously submitted transaction:

GET https://api.moala.africa/v1/api/transaction/check/{partnerId}

Sending the Status Request

import Utils;

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import java.time.Instant;

public class StatusCheck {
    private static final String API_KEY = "votre_api_key";
    private static final String SECRET_KEY = "votre_secret_key";
    private static final String API_BASE_URL = "https://api.moala.africa";

    public static void checkStatus(String partnerId) {
        try (CloseableHttpClient client = HttpClients.createDefault()) {
            String endpoint = "/v1/api/transaction/check/" + partnerId;
            String url = API_BASE_URL + endpoint;
            long timestamp = Instant.now().getEpochSecond();
            String payload = "";

            String method = "GET";
            String signature = Utils.generateSignature(SECRET_KEY, String.valueOf(timestamp), method, endpoint, payload);

            HttpGet get = new HttpGet(url);
            get.setHeader("LP-ACCESS-KEY", API_KEY);
            get.setHeader("LP-ACCESS-TIMESTAMP", String.valueOf(timestamp));
            get.setHeader("LP-ACCESS-SIGN", signature);

            CloseableHttpResponse response = client.execute(get);
            System.out.println(EntityUtils.toString(response.getEntity()));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

4. Execute the Code

Let’s now run the code above by attempting to withdraw 500 F.

import Withdrawal;
import StatusCheck;

public static void main(String args[]) {
    String API_KEY = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    String SECRET_KEY = "yyyyyyyyyyyyyyyyyyyyyyyyyyy";
    String serviceCode = "CASHOUT_ORANGE_CM";
    String phoneNumber = "XXXXXXXXX";
    String partnerId = "xxxxxxxx";
    Float amount = 1000f;

    Withdrawal withdrawal = new Withdrawal();
    withdrawal.API_KEY = API_KEY;
    withdrawal.SECRET_KEY = SECRET_KEY;
    withdrawal.makeWithdrawal(amount, serviceCode, phoneNumber, partnerId);

    StatusCheck statusCheck = new StatusCheck();
    statusCheck.API_KEY = API_KEY;
    statusCheck.SECRET_KEY = SECRET_KEY;
    statusCheck.checkStatus(partnerId);
}

5. Conclusion

At the end of this tutorial, you now know how to integrate MOALA's APIs to perform a cash withdrawal operation.