RetrievePaymentRestAdapter.java

public class RetrievePaymentRestAdapter implements JavaDelegate {
  @Inject private OrderRepository orderRepository; // e.g. using Spring
  @Inject private RestTemplate rest; // e.g. using Spring
  
  public void execute(DelegateExecution context) throws Exception {
    // Input mapping
    String orderId = context.getVariable("orderId");
    Order o = orderRepository.findOrder(orderId);    
    CreateChargeRequest request = new CreateChargeRequest();
    request.setAmount( o.getAmount() );
    
    // Service call by technology of choice (e.g. Spring RestTemplate)
    CreateChargeResponse response = rest.postForObject("https://api.stripe.com", 
        request, CreateChargeResponse.class);
    
    // Output mapping
    context.setVariable("stripeTransactionId", response.getBalanceTransaction());
}