Jakarta ee PayPal REST API未执行付款。无法将付款对象的状态从'；创建'；至'；批准'；或'；已完成'；

我正在使用servlet生成HTML页面，这些页面旨在使用新的RESTAPI执行PayPal支付。我还无法生成状态为“已批准”或“已创建”的付款。我尝试了github页面上PaymentWithPayPalServlet.java示例的变体，并在下面列出了最接近的变体。我最不清楚哪个对象应该接收更新状态“已批准”或“已完成”以及何时接收

虽然我在下面包含了完整的代码，但这里是我的想法的一个快速分解。也许有人能纠正我的错误

我创建了一个具有所有适当属性集的付款对象

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”。在我的代码结束时，我将用户重定向到payPal页面，我假设payPal会在执行之前批准付款。注意，这与示例文件有偏差，但我不理解为什么这不起作用

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

由于payPal无法通过HTTP协议更改我的局部变量createdPayment的状态，因此我希望payPal页面重定向回我的returnURL页面，并在URL后面附加paymentID和可能的授权令牌。使用这两种方法，我希望通过某种类型的静态函数调用从payPal服务器检索支付对象，如：

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

但是，URL没有附加任何paymentID。相反，这里有一个payerID。此外，我从payPal服务器检索状态为“已批准”或“已完成”的支付对象的所有尝试均失败。基本上，我尝试了以下方面的变化，但没有成功：

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

如果有人能告诉我我的推理哪里出了问题，那绝对会让人震惊。谢谢下面是我的servlet主页的完整代码。注意，returnURL会将您带回同一页面，在该页面中，它会找到payPal的HTTP请求中包含的PayRid，并正确地输入主if-else语句的“if”块，这会生成一些完全没有帮助的基本输出。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);
    }

公共类PaymentInfoServlet2扩展了HttpServlet{
私有静态最终长serialVersionUID=1L；
//专用静态最终记录器=记录器
//.getLogger（PaymentWithPayPalServlet.class）；
Map Map=newhashmap（）；
public void init（ServletConfig ServletConfig）抛出ServletException{
//##负载配置
//加载的SDK配置
//资源。此初始化代码可以是
//作为initservlet完成。
InputStream is=PaymentInfoServlet2.class
.getResourceAsStream（“/sdk_config.properties”）；
试一试{
PayPalResource.initConfig（is）；
}捕获（Paypalreste例外）{
//LOGGER.fatal（如getMessage（））；
}
}
@凌驾
受保护的无效数据集（HttpServletRequest-req、HttpServletResponse-resp）
抛出ServletException、IOException{
doPost（请求、响应）；
}
//##创建
//显示使用PayPal创建付款的示例
@凌驾
受保护的void doPost（HttpServletRequest-req、HttpServletResponse-resp）
抛出ServletException、IOException{
//####访问令牌
//从中检索访问令牌
//OAuthTokenCredential通过传入
//ClientID和ClientSecret
APIContext APIContext=null；
字符串accessToken=null；
试一试{
AccessToken access=新的AccessToken（PublicUtils.getUser（），PublicUtils.getPass（），req，resp）；
accessToken=access.getToken（）；
//####Api上下文
//传入'ApiContext'对象以进行身份验证
//调用并发送唯一的请求id
//（这确保了幂等性）
//如果未显式传递请求id，则为请求id。
apiContext=access.getContext（）；
//如果要传入请求id，请使用此变量
//理想情况下，这在您的应用程序中是有意义的
//订单号。
/*
*字符串requestId=Long.toString（System.nanoTime（）；APIContext
*apiContext=新的apiContext（accessToken，requestId））；
*/
}捕获（例外e）{
setAttribute（“错误”，例如getMessage（））；
}
if（req.getParameter（“PayerID”）！=null）{
付款=新付款（）；
if（req.getParameter（“guid”）！=null）{
payment.setId（map.get（req.getParameter（“guid”））；
}
PaymentExecution PaymentExecution=新的PaymentExecution（）；
paymentExecution.setPayerId（请求getParameter（“PayerID”）；
试一试{
payment.execute（apiContext，paymentexecute）；
req.setAttribute（“response”，Payment.getLastResponse（））；
}捕获（Paypalreste例外）{
setAttribute（“错误”，例如getMessage（））；
}
PrintWriter out=resp.getWriter（）；
println（“这是returnURL页面”）；
out.println（“paymentID=“+payment.getId（））；
out.println（“pamentState=“+payment.getState（））；
out.println（“executedPayerID=“+paymentExecution.getPayerId（））；
//出局，普林
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);
    }
}

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);

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);

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

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

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

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

{
    "id": "PAY-50299450TD463315FK4MDBAI",
    "intent": "sale",
    "state": "created",
    "payer": {
        "payment_method": "paypal"
        },
"transactions": [
{
  "amount": {
    "total": "7.00",
    "currency": "USD",
    "details": {
      "subtotal": "5.00",
      "tax": "1.00",
      "shipping": "1.00"
    }
  },
  "description": "This is the payment transaction description.",
  "item_list": {
    "items": [
      {
        "name": "Ground Coffee 40 oz",
        "price": "5.00",
        "currency": "USD",
        "quantity": 1
      }
    ]
  },
  "related_resources": []
}],
"create_time": "2016-04-21T01:44:32Z",
"links": [
{
  "href": "https://api.sandbox.paypal.com/v1/payments/payment/PAY-50299450TD463315FK4MDBAI",
  "rel": "self",
  "method": "GET"
},
{
  "href": "https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=EC-27C19584EL875221E",
  "rel": "approval_url",
  "method": "REDIRECT"
},
{
  "href": "https://api.sandbox.paypal.com/v1/payments/payment/PAY-50299450TD463315FK4MDBAI/execute",
  "rel": "execute",
  "method": "POST"
}]}