How to Use Stripe Billing API for Subscription Management in Java

Initialize Stripe in Java

• Include Stripe's Java library in your project. You'll need Maven or Gradle to manage dependencies. Here's how you can add Stripe to your project using Maven:

<dependency>
  <groupId>com.stripe</groupId>
  <artifactId>stripe-java</artifactId>
  <version>20.91.0</version>
</dependency>

• Set the API key in your Java code. Ensure this is kept secure and not exposed in public code repositories.

import com.stripe.Stripe;

public class StripeConfig {
  public StripeConfig() {
    Stripe.apiKey = "your_secret_key"; // Replace with your actual secret key
  }
}

Create a Customer

• To manage subscriptions, you first need to create a customer in Stripe. This will be tied to the user's account in your system.

import com.stripe.exception.StripeException;
import com.stripe.model.Customer;
import com.stripe.param.CustomerCreateParams;

public class CustomerService {

  public Customer createCustomer(String email) throws StripeException {
    CustomerCreateParams params = CustomerCreateParams.builder()
        .setEmail(email)
        .build();

    return Customer.create(params);
  }
}

Create a Subscription

• To create a subscription, ensure you have set up a pricing plan in Stripe Dashboard. Use the plan ID in the API call to initiate a subscription.

import com.stripe.model.Subscription;
import com.stripe.param.SubscriptionCreateParams;

public class SubscriptionService {
  
  public Subscription createSubscription(String customerId, String priceId) throws StripeException {
    SubscriptionCreateParams params = SubscriptionCreateParams.builder()
        .setCustomer(customerId)
        .addItem(SubscriptionCreateParams.Item.builder().setPrice(priceId).build())
        .build();

    return Subscription.create(params);
  }
}

Handle Subscription Events with Webhooks

• Stripe webhooks notify your application of subscription events such as creation, update, or payment failures. Set up a webhook endpoint in your application and configure it in the Stripe Dashboard.

import com.stripe.net.Webhook;
import com.stripe.model.Event;

public class WebhookHandler {

  private static final String endpointSecret = "your_endpoint_secret";

  public void handleWebhook(String payload, String sigHeader) {
    Event event = null;
    try {
      event = Webhook.constructEvent(payload, sigHeader, endpointSecret);
    } catch (Exception e) {
      // Handle webhook signature verification failure
      e.printStackTrace();
    }
    
    switch (event.getType()) {
      case "invoice.payment_succeeded":
        // Handle successful payment
        break;
      case "customer.subscription.deleted":
        // Handle subscription cancellation
        break;
      default:
        // Handle other event types
        break;
    }
  }
}

Cancel a Subscription

• To cancel a subscription, use the subscription ID to perform the cancellation API call.

import com.stripe.model.Subscription;

public class SubscriptionCancellationService {

  public Subscription cancelSubscription(String subscriptionId) throws StripeException {
    Subscription subscription = Subscription.retrieve(subscriptionId);
    return subscription.cancel();
  }
}

Prorate Subscriptions

• When updating a subscription, Stripe automatically prorates the charge by default. This can be configured to meet your system needs. Here’s how to update and prorate a subscription.

import com.stripe.param.SubscriptionUpdateParams;

public class SubscriptionUpdateService {

  public Subscription updateSubscription(String subscriptionId, String newPriceId) throws StripeException {
    Subscription subscription = Subscription.retrieve(subscriptionId);
    
    SubscriptionUpdateParams params = SubscriptionUpdateParams.builder()
        .addItem(SubscriptionUpdateParams.Item.builder().setPrice(newPriceId).build())
        .setProrationBehavior(SubscriptionUpdateParams.ProrationBehavior.CREATE_INVOICE)
        .build();

    return subscription.update(params);
  }
}

Testing with Stripe API Keys

• Use test API keys provided by Stripe for development and testing. This allows simulation of various scenarios like successful transactions, declined payments, and webhooks without affecting real transactions.

export STRIPE_TEST_KEY=your_test_key

By utilizing the Stripe Java library, you can effectively manage subscriptions within your Java applications, handle Stripe events via webhooks, and customize the subscription lifecycle to fit your application's needs.