jakarta-ee - PayPal REST API未执行付款。无法将付款对象的状态从“已创建”更改为“已批准”或“已完成”

Question

我正在使用Servlet生成HTML页面，这些页面旨在使用新的REST API执行PayPal付款。我尚未能够生成状态为已批准或已创建的付款。我已经从github页面上的PaymentWithPayPalServlet.java示例中尝试了变体，并且在下面添加了最接近的变体。对于哪个对象应该接收“已批准”或“已完成”的更新状态以及何时接收，我不清楚。

尽管我在下面包括了完整的代码，但是这里是我的想法的快速分解。也许有人可以纠正我哪里出错了...

我创建了一个包含所有适当属性/属性的Payment对象。

Payment payment = new Payment();
payment.setIntent("sale");
payment.setPayer(payer);
payment.setTransactions(transactions);
payment.setRedirectUrls(redirectUrls);
Payment createdPayment = payment.create(apiContext);

现在，createdPayment对象的状态为“已创建”。在代码末尾，我将用户重定向到payPal页面，在该页面上我假设payPal将在执行之前批准付款。请注意，这与示例文件有所不同，但我不明白为什么这不起作用。

if (link.getRel().equalsIgnoreCase("approval_url")) 
{
         req.setAttribute("redirectURL", link.getHref());
         resp.sendRedirect(link.getHref());
}

由于payPal无法通过HTTP协议更改我的本地变量createdPayment的状态，因此我希望payPal页面重定向回我的returnURL页面，其中带有paymentID和可能附加在URL上的授权令牌。使用这两件事，我希望可以使用某种类型的静态函数调用从payPal服务器检索付款对象，例如：

String authToken=req.getParameter("token");
String paymentID=req.getParameter("paymentID");
Payment approvedPayment=Payment.getPaymentObject(authToken,paymentID);

但是，该URL没有附加任何paymentID。而是有一个payerID。此外，我所有从PayPal服务器检索状态为“已批准”或“已完成”的付款对象的尝试均失败了。基本上，我尝试了以下变化，但均无济于事：

String authToken=req.getParameter("token");
String paymentID=req.getParameter("payerID");
Payment approvedPayment=Payment.get(authToken,payerID);

如果有人可以提示我我的推理出了问题的地方，那绝对是很糟糕的。谢谢！这是我的主要servlet页面中的完整代码。注意，returnURL带您回到同一页面，在该页面中找到来自payPal的HTTP请求中包含的payerID，并正确输入主if-else语句的'if'块，这会生成一些完全无用的基本输出。还要注意，我已经将一些基本函数调用（如检索访问令牌和上下文）外包给了其他类，如AccessToken类。

public class PaymentInfoServlet2 extends HttpServlet {

    private static final long serialVersionUID = 1L;

   // private static final Logger LOGGER = Logger
     //               .getLogger(PaymentWithPayPalServlet.class);
    Map<String, String> map = new HashMap<String, String>();

    public void init(ServletConfig servletConfig) throws ServletException {
            // ##Load Configuration
            // Load SDK configuration for
            // the resource. This intialization code can be
            // done as Init Servlet.
            InputStream is = PaymentInfoServlet2.class
                            .getResourceAsStream("/sdk_config.properties");
            try {
                    PayPalResource.initConfig(is);
            } catch (PayPalRESTException e) {
                  //  LOGGER.fatal(e.getMessage());
            }

    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
                    throws ServletException, IOException {
            doPost(req, resp);
    }

    // ##Create
    // Sample showing to create a Payment using PayPal
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
                    throws ServletException, IOException {
            // ###AccessToken
            // Retrieve the access token from
            // OAuthTokenCredential by passing in
            // ClientID and ClientSecret
            APIContext apiContext = null;
            String accessToken = null;
            try {
                AccessToken access=new AccessToken(PublicUtils.getUser(),PublicUtils.getPass(),req,resp);

                    accessToken = access.getToken();

                    // ### Api Context
                    // Pass in a `ApiContext` object to authenticate
                    // the call and to send a unique request id
                    // (that ensures idempotency). The SDK generates
                    // a request id if you do not pass one explicitly.
                    apiContext = access.getContext();
                    // Use this variant if you want to pass in a request id
                    // that is meaningful in your application, ideally
                    // a order id.
                    /*
                     * String requestId = Long.toString(System.nanoTime(); APIContext
                     * apiContext = new APIContext(accessToken, requestId ));
                     */
            } catch (Exception e) {
                    req.setAttribute("error", e.getMessage());
            }
            if (req.getParameter("PayerID") != null) {
                    Payment payment = new Payment();
                    if (req.getParameter("guid") != null) {
                            payment.setId(map.get(req.getParameter("guid")));
                    }

                    PaymentExecution paymentExecution = new PaymentExecution();
                    paymentExecution.setPayerId(req.getParameter("PayerID"));
                    try {
                            payment.execute(apiContext, paymentExecution);
                            req.setAttribute("response", Payment.getLastResponse());
                    } catch (PayPalRESTException e) {
                            req.setAttribute("error", e.getMessage());
                    }
                    PrintWriter out=resp.getWriter();
                    out.println("This is the returnURL page.");
                    out.println("paymentID="+payment.getId());
                    out.println("pamentState="+payment.getState());
                    out.println("executedPayerID="+paymentExecution.getPayerId());
                   // out.println("executedTransaction: "+paymentExecution.getTransactions().get(0).toString());
            } else {

                    // ###Details
                    // Let's you specify details of a payment amount.
                    Details details = new Details();
                    details.setShipping("1");
                    details.setSubtotal("5");
                    details.setTax("1");

                    // ###Amount
                    // Let's you specify a payment amount.
                    Amount amount = new Amount();
                    amount.setCurrency("USD");
                    // Total must be equal to sum of shipping, tax and subtotal.
                    amount.setTotal("7");
                    amount.setDetails(details);

                    // ###Transaction
                    // A transaction defines the contract of a
                    // payment - what is the payment for and who
                    // is fulfilling it. Transaction is created with
                    // a `Payee` and `Amount` types
                    Transaction transaction = new Transaction();
                    transaction.setAmount(amount);
                    transaction
                                    .setDescription("This is the payment transaction description.");

                    // The Payment creation API requires a list of
                    // Transaction; add the created `Transaction`
                    // to a List
                    List<Transaction> transactions = new ArrayList<Transaction>();
                    transactions.add(transaction);

                    // ###Payer
                    // A resource representing a Payer that funds a payment
                    // Payment Method
                    // as 'paypal'
                    Payer payer = new Payer();
                    payer.setPaymentMethod("paypal");

                    // ###Payment
                    // A Payment Resource; create one using
                    // the above types and intent as 'sale'
                    Payment payment = new Payment();
                    payment.setIntent("sale");
                    payment.setPayer(payer);
                    payment.setTransactions(transactions);

                    // ###Redirect URLs
                    RedirectUrls redirectUrls = new RedirectUrls();
                    String guid = UUID.randomUUID().toString().replaceAll("-", "");
                    redirectUrls.setCancelUrl(req.getScheme() + "://"
                                    + req.getServerName() + ":" + req.getServerPort()
                                    + req.getContextPath() + "/CancelServlet?guid=" + guid);
                    redirectUrls.setReturnUrl(req.getScheme() + "://"
                                    + req.getServerName() + ":" + req.getServerPort()
                                    + req.getContextPath() + "/PaymentInfoServlet2?guid=" + guid);
                    payment.setRedirectUrls(redirectUrls);

                    // Create a payment by posting to the APIService
                    // using a valid AccessToken
                    // The return object contains the status;
                    try {
                            Payment createdPayment = payment.create(apiContext);
                         //   LOGGER.info("Created payment with id = "
                           //                 + createdPayment.getId() + " and status = "
                             //               + createdPayment.getState());
                            // ###Payment Approval Url
                            Iterator<Links> links = createdPayment.getLinks().iterator();
                            while (links.hasNext()) {
                                    Links link = links.next();
                                    if (link.getRel().equalsIgnoreCase("approval_url")) {
                                            req.setAttribute("redirectURL", link.getHref());
                                            resp.sendRedirect(link.getHref());
                                    }
                            }
                            req.setAttribute("response", Payment.getLastResponse());
                            map.put(guid, createdPayment.getId());
                    } catch (PayPalRESTException e) {
                            req.setAttribute("error", e.getMessage());
                    }
            }
            req.setAttribute("request", Payment.getLastRequest());
            //req.getRequestDispatcher("response.jsp").forward(req, resp);
    }

}



为了回应我在下面的第一个评论者Yozha Karlov，我添加了以下内容：

好吧，我想我对此有几个反应。首先，谢谢。第二，我想也许我对我的问题还不够清楚。我对如何检索旧的付款对象（在上面名为“ createdPayment”）不感到困惑。在上面复制的完整代码中，我使用与您引用的完全相同的guid代码。这样做的一个问题是，除了将createdPayment对象的ID复制到新的空白Payment对象之外，它什么也不做。新对象的状态以及其他所有属性仍然为空白。它是一个具有ID的空白对象，仅此而已。几乎一文不值，所以我要么丢失了某些东西，要么示例servlet是完全错误的。

实际上，我的初始方法是创建一个带有静态映射的静态类，以将sessionID映射到HttpSession对象。我将为用户的浏览器会话生成一个sessionID，并将该sessID附加到payment.create（）方法的redirectURLs中的cancelURL和returnURL中。然后，我将确保相关的Payment对象已附加到用户的HttpSession对象中，以便以后在returnURL servlet中进行检索。

public class SessionStore {
    public static Map<String, HttpSession> map = new HashMap<String,HttpSession>();
}

and in my main servlet, called PaymentInfoServlet2, here is the relevant code that i execute before the servlet ends and the user is re-directed to the payPal pages:

HttpSession sess=req.getSession();
String sessID=sess.getId();
SessionStore.map.put(sessID, sess);

// append sessID to redirectURLs - the URLs that the payPal pages return back to
approveURL=req.getScheme() + "://"+ req.getServerName() + ":" +req.getServerPort()+ req.getContextPath() +"/ApproveServlet?sessID=" +sess.getId();
cancelURL=req.getScheme() + "://"+ req.getServerName() + ":" + req.getServerPort()+ req.getContextPath() +"/CancelServlet?sessID=" +sess.getId();
redirectUrls.setCancelUrl(cancelURL);
redirectUrls.setReturnUrl(approveURL);
payment.setRedirectUrls(redirectUrls);

// create the payment on the payPal server
Payment createdPayment = payment.create(access.getContext());

//add created Payment object to HttpSession object.
ArrayList<Payment> createdPayments=new ArrayList<Payment>();
createdPayments.add(createdPayment);
sess.setAttribute("createdPayments", createdPayments);

// redirect to payPal pages
Iterator<Links> links = createdPayment.getLinks().iterator();
while (links.hasNext()) 
{
    Links link = links.next();
    if (link.getRel().equalsIgnoreCase("approval_url")) 
    {
            url=link.getHref();
        resp.sendRedirect(url);
    }
}

然后，当payPal页面将我返回到我以前的returnURL页面时，我将调用以下相关代码片段：

String sessID=req.getParameter("sessID");
HttpSession sess=SessionStore.map.get(sessID);
ArrayList<Payment> cPay=(ArrayList<Payment>)sess.getAttribute("createdPayments");
Payment payment=(Payment)cPay.get(0);

并且已检索到具有所有相同属性和所有内容的旧付款对象。这似乎比仅将旧付款ID复制到否则为空白的Payment对象中更为有用。但是，旧的“ createdPayment”状态仍为“已创建”，而不是“已批准”或“已完成”。我不知道如何从上面概述的对象创建到执行相同的Payment对象的过程。实际上，我什至不知道是否应该使用相同的付款对象创建并执行使用method ='paypal'的付款。正如我在原始帖子中所描述的那样，对我来说这应该没有意义。我创建了一个付款对象，payPal发回了一个roval_URL，其中包括我，用于将用户重定向到以进行批准。这会将用户带离我的Web应用程序，并进入Pay​​Pal服务器。由于payPal无法修改我的本地“ createdPayment”变量，因此payPal无法更改其状态。此外，似乎我需要状态为“已批准”的Payment对象才能执行付款。因此，我得出结论，贝宝（PayPal）必须发送给我一个新的付款对象，该对象应具有与我的“ createdPayment”对象相同的信息，但是要具有已批准状态的更新状态，并且可能需要一个特殊的令牌/密码来指示已批准状态，以防止他人只需将一大笔付款入侵已批准状态即可，这很容易做到。我看到我正在按预期方式获得令牌，但没有按预期方式获得PaymentID。我正在获取一个payerID。有没有一种方法可以将返回的令牌和payerID转换为状态为“已批准”的新Payment对象，或者我只是完全丢失了某些东西？

Answer 1

没错，从PayPal网站页面重定向后，“ payerId”将被附加为请求参数，而不是付款ID。但是您还需要付款ID才能执行它。这是来自payPal interactive tool的代码。

String accessToken = "Bearer Jfdd4h4VrmvLeATBNPsGOpp7pMosTppiy.Jq6xpwQ6E";
APIContext apiContext = new APIContext(accessToken);
apiContext.setConfigurationMap(sdkConfig);

Payment payment = new Payment("PAY-4AL22602580048540KKPBSNY");
PaymentExecution paymentExecute = new PaymentExecution();
paymentExecute.setPayerId("BKJ78SZZ8KJYY");
payment.execute(apiContext, paymentExecute);

因此，棘手的部分是如何保留请求之间的付款ID，因为众所周知，HTTP不保存任何状态。您可以在所引用的示例中查看其实现方式：

https://github.com/paypal/rest-api-sdk-java/blob/master/rest-api-sample/src/main/java/com/paypal/api/payments/servlet/PaymentWithPayPalServlet.java

因此它们生成uuid：

String guid = UUID.randomUUID().toString().replaceAll("-", "");

在重定向网址中添加guid参数：

redirectUrls.setReturnUrl(req.getScheme() + "://"
      + req.getServerName() + ":" + req.getServerPort()
      + req.getContextPath() + "/paymentwithpaypal?guid=" + guid);

并将此guid参数与创建的付款ID关联：

map.put(guid, createdPayment.getId());

为了以后使用

payment.setId(map.get(req.getParameter("guid")));

希望这会有所帮助