Java对接PayPal进行付款

大家好，我是傻明蚕豆，今天为大家带来的是PayPal付款的一个栗子。

首先打开地址：https://developer.paypal.com/，自己注册一个账号，登录后页面如下：

按照上图所示，在沙箱里面创建两个帐号，一个商家，一个买家，参数自己设置，使用默认的帐号也可以。

接着按照下图所示，创建一个沙箱app。

点击该app，即可获取到Client ID和Secret，如下图所示：

到这里准备工作就完成了，下面开始Java和PayPal对接，完成一个完整的付款流程。

首先当然是创建一个springboot项目，然后引入PayPal的依赖：

<dependency>
			<groupId>com.paypal.sdk</groupId>
			<artifactId>rest-api-sdk</artifactId>
			<version>1.4.2</version>
</dependency>

然后配置application.properties

paypal.mode=sandbox #沙箱环境
paypal.client.app=这里是Client ID
paypal.client.secret=这里是Secret

接着创建页面index.html

<!DOCTYPE html>
<html xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8" />
    <title>Insert title here</title>
</head>
<body>
<form method="post" action="/paypal/pay">
    <button type="submit">我要支付</button>
</form>
</body>
</html>

支付成功后跳转的页面success.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8" />
    <title>Insert title here</title>
</head>
<body>
<h1>支付成功了</h1>
</body>
</html>

支付取消跳转页面cancel.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8" />
    <title>Insert title here</title>
</head>
<body>
<h1>支付取消鸟！！！</h1>
</body>
</html>

开始写接口：

import com.paypal.api.payments.*;
import com.paypal.base.rest.PayPalRESTException;
import com.sillyming.test.service.PaypalService;
import com.sillyming.test.utils.URLUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import javax.servlet.http.HttpServletRequest;

@Controller
@RequestMapping("/paypal")
public class PayPalController {

    public static final String SUCCESS_URL = "pay/success";
    public static final String CANCEL_URL = "pay/cancel";

    private Logger log = LoggerFactory.getLogger(getClass());

    @Autowired
    private PaypalService paypalService;

    @RequestMapping(method = RequestMethod.GET ,value = "/index")
    public String index(){
        return "paypal/index";
    }

    @RequestMapping(method = RequestMethod.POST, value = "pay")
    public String pay(HttpServletRequest request){
        //定义支付成功和取消支付跳转url
        String cancelUrl = URLUtils.getBaseURl(request) + "/paypal/" + CANCEL_URL;
        String successUrl = URLUtils.getBaseURl(request) + "/paypal/" + SUCCESS_URL;
        String invoiceNumber="123456abc";//自定义一个账单号
        try {
            Payment payment = paypalService.createPayment(
                    "100.01",//支付金额
                    "USD",//金额的币种
                    "订单描述",
                    cancelUrl,
                    successUrl,invoiceNumber);
            System.out.println("payment id:"+payment.getId());
            System.out.println("payment state:"+payment.getState());
            System.out.println("payment invoiceNumber:"+payment.getTransactions().get(0).getInvoiceNumber());
            //这里成功返回payment对象，表示PayPal那边已经成功创建订单。
            for(Links links : payment.getLinks()){
                if(links.getRel().equals("approval_url")){
                    System.out.println("create payment success");
                    return "redirect:" + links.getHref();//把买家重定向到支付页面
                }
            }
        } catch (PayPalRESTException e) {
            log.error(e.getMessage());
        }
        return "redirect:/";
    }

    @RequestMapping(method = RequestMethod.GET, value = CANCEL_URL)
    public String cancelPayment(){
        return "paypal/cancel";
    }

    @RequestMapping(method = RequestMethod.GET, value = SUCCESS_URL)
    public String successPayment(@RequestParam("paymentId") String paymentId, @RequestParam("PayerID") String payerId){
        try {
            System.out.println("start execute payment.");
            Payment payment = paypalService.executePayment(paymentId, payerId);//买家授权支付
            System.out.println("payment id:"+payment.getId());
            System.out.println("payment state:"+payment.getState());
            // 订单总价
            String total = payment.getTransactions().get(0).getAmount().getTotal();
            System.out.println("payment total:"+total);
            String orderId = payment.getTransactions().get(0).getRelatedResources().get(0).getOrder().getId();
            System.out.println("payment invoiceNumber:"+payment.getTransactions().get(0).getInvoiceNumber());
            System.out.println("payment orderId:"+orderId);
            System.out.println("end execute payment.");
            System.out.println();

            System.out.println("start capture payment.");
            Capture capture=paypalService.capturePayment(total,payment.getTransactions().get(0).getAmount().getCurrency(),orderId);//捕获到买家授权的订单，整个过程到这里就完成了。
            System.out.println("Capture id = " + capture.getId() + " and status = " + capture.getState());
            if(payment.getState().equals("completed")){
                return "paypal/success";
            }
        } catch (PayPalRESTException e) {
            log.error(e.getMessage());
        }
        return "redirect:/";
    }

}

URLUtils

public class URLUtils {

    public static String getBaseURl(HttpServletRequest request) {
        String scheme = request.getScheme();
        String serverName = request.getServerName();
        int serverPort = request.getServerPort();
        String contextPath = request.getContextPath();
        StringBuffer url =  new StringBuffer();
        url.append(scheme).append("://").append(serverName);
        if ((serverPort != 80) && (serverPort != 443)) {
            url.append(":").append(serverPort);
        }
        url.append(contextPath);
        if(url.toString().endsWith("/")){
            url.append("/");
        }
        return url.toString();
    }

}

PaypalService

import com.paypal.api.payments.*;
import com.paypal.base.rest.APIContext;
import com.paypal.base.rest.PayPalRESTException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

import com.sillyming.test.common.Constant;

@Service
public class PaypalService {

    private Logger log = LoggerFactory.getLogger(getClass());

    @Autowired
    private APIContext apiContext;

    public Payment createPayment(
            String total,
            String currency,
            String description,
            String cancelUrl,
            String successUrl,String invoiceNumber) throws PayPalRESTException {
        Amount amount = new Amount();
        amount.setCurrency(currency);
        amount.setTotal(total);
        Details details=new Details();
        details.setSubtotal(total);
        amount.setDetails(details);
        Transaction transaction = new Transaction();
        transaction.setDescription(description);
        transaction.setAmount(amount);
        transaction.setInvoiceNumber(invoiceNumber);

        List<Transaction> transactions = new ArrayList<>();
        transactions.add(transaction);

        Payer payer = new Payer();
        payer.setPaymentMethod(Constant.PAYMENT_METHOD_PAYPAL);

        Payment payment = new Payment();
        payment.setIntent(Constant.PAYMENT_INTENT_ORDER);
        payment.setPayer(payer);
        payment.setTransactions(transactions);
        RedirectUrls redirectUrls = new RedirectUrls();
        redirectUrls.setCancelUrl(cancelUrl);
        redirectUrls.setReturnUrl(successUrl);
        payment.setRedirectUrls(redirectUrls);

        return payment.create(apiContext);
    }

    public Payment executePayment(String paymentId, String payerId) throws PayPalRESTException{
        Payment payment = new Payment();
        payment.setId(paymentId);
        PaymentExecution paymentExecute = new PaymentExecution();
        paymentExecute.setPayerId(payerId);
        return payment.execute(apiContext, paymentExecute);
    }

    public Capture capturePayment(String total,String currency,String orderId){
        try{
            Amount amount = new Amount();
            amount.setCurrency(currency);
            amount.setTotal(total);

            // Authorize order
            Order order = new Order();
            order = Order.get(apiContext, orderId);
            order.setAmount(amount);
            Authorization authorization = order.authorize(apiContext);

            // Capture payment
            Capture capture = new Capture();
            capture.setAmount(amount);
            capture.setIsFinalCapture(true);

            Capture responseCapture = authorization.capture(apiContext, capture);
            return responseCapture;

        } catch (PayPalRESTException e) {
            log.error(e.getMessage());
            return null;
        }
    }

}

PaypalService 这个类，具体可以参考官方文档：https://developer.paypal.com/docs/api/quickstart/create-process-order/

Constant

public final class Constant {
	public static final int CODE_SUCCESS=1;
	public static final int CODE_ERROR=-1;
	public static final String CODE_SUCCESS_STRING="success";
	public static final String CODE_ERROR_STRING="error";

	public static final String PAYMENT_METHOD_PAYPAL="paypal";
	public static final String PAYMENT_METHOD_CREDIT_CARD="credit_card";

	public static final String PAYMENT_INTENT_ORDER="order";
	public static final String PAYMENT_INTENT_SALE="sale";
	public static final String PAYMENT_INTENT_AUTHORIZE="authorize";

}