NajeebArif

//...

@Override
@SneakyThrows
public void captureOrder(String orderId) {
    final OrdersCaptureRequest ordersCaptureRequest = new OrdersCaptureRequest(orderId);
    final HttpResponse<Order> httpResponse = payPalHttpClient.execute(ordersCaptureRequest);
    log.info("Order Capture Status: {}",httpResponse.result().status());
}

NajeebArif

//...

private String orderId = "";

@GetMapping
public String orderPage(Model model){
    model.addAttribute("orderId",orderId);
    return "order";
}

NajeebArif

//...

@PostMapping
public String placeOrder(@RequestParam Double totalAmount, HttpServletRequest request){
    final URI returnUrl = buildReturnUrl(request);
    CreatedOrder createdOrder = paymentService.createOrder(totalAmount, returnUrl);
    return "redirect:"+createdOrder.getApprovalLink();
}

//...

NajeebArif

//...

@Override
@SneakyThrows
public CreatedOrder createOrder(Double totalAmount, URI returnUrl) {
    final OrderRequest orderRequest = createOrderRequest(totalAmount, returnUrl);
    final OrdersCreateRequest ordersCreateRequest = new OrdersCreateRequest().requestBody(orderRequest);
    final HttpResponse<Order> orderHttpResponse = payPalHttpClient.execute(ordersCreateRequest);
    final Order order = orderHttpResponse.result();
    LinkDescription approveUri = extractApprovalLink(order);

NajeebArif

@Service
public class PayPayPaymentService implements PaymentService{

    private final PayPalHttpClient payPalHttpClient;

    public PayPayPaymentService(@Value("${paypal.clientId}") String clientId,
                                @Value("${paypal.clientSecret}") String clientSecret) {
        payPalHttpClient = new PayPalHttpClient(new PayPalEnvironment.Sandbox(clientId, clientSecret));
    }

NajeebArif

paypal:
  clientId: ${paypal.clientId}
  clientSecret: ${paypal.secret}

NajeebArif

public interface PaymentService {
    CreatedOrder createOrder(Double totalAmount, URI returnUrl);
}

NajeebArif

@Data
public class CreatedOrder {
    private final String orderId;
    private final URI approvalLink;
}

NajeebArif

//...

private final PaymentService paymentService;

public OrderController(PaymentService paymentService) {
    this.paymentService = paymentService;
}

@PostMapping
public String placeOrder(@RequestParam Double totalAmount, HttpServletRequest request){

NajeebArif

//...

@GetMapping("/capture")
public String captureOrder(){
    return "";
}

@PostMapping
public String placeOrder(@RequestParam Double amountId, HttpServletRequest request){
    final URI returnUrl = buildReturnUrl(request);