<dependency>
 <groupId>com.alipay.sdk</groupId>
 <artifactId>alipay-easysdk</artifactId>
 <version>2.2.0</version>
</dependency>

package com.example.demo.common.config;

import com.alipay.easysdk.factory.Factory;
import com.alipay.easysdk.kernel.Config;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;

@Data
@Component
@ConfigurationProperties(prefix = "alipay")
public class AliPayConfig {
    private String appId;
    private String appPrivateKey;
    private String alipayPublicKey;
    private String notifyUrl;


    @PostConstruct
    public void init() {
        // 設置參數（全局只需設置一次）
        Config options = getOptions();
        options.appId = this.appId;
        options.merchantPrivateKey = this.appPrivateKey;
        options.alipayPublicKey = this.alipayPublicKey;
        options.notifyUrl = this.notifyUrl;
        Factory.setOptions(options);
        System.out.println("=======支付寶SDK初始化成功=======");
    }

    private Config getOptions() {
        Config config = new Config();
        config.protocol = "https";
        config.gatewayHost = "openapi.alipaydev.com";
        config.signType = "RSA2";
        return config;
    }

}

 @GetMapping("/pay")
    public String pay(AliPay aliPay) {
        AlipayTradePagePayResponse response;
        try {
            //  發(fā)起API調用（以創(chuàng)建當面付收款二維碼為例）
            response = Factory.Payment.Page()
                    .pay(aliPay.getSubject(), aliPay.getTraceNo(), aliPay.getTotalAmount(), "");
        } catch (Exception e) {
            System.err.println("調用遭遇異常，原因：" + e.getMessage());
            throw new RuntimeException(e.getMessage(), e);
        }
        return response.getBody();
    }

@PostMapping("/notify")  // 注意這里必須是POST接口
    public String payNotify(HttpServletRequest request) throws Exception {
        if (request.getParameter("trade_status").equals("TRADE_SUCCESS")) {
            System.out.println("=========支付寶異步回調========");

            Map<String, String> params = new HashMap<>();
            Map<String, String[]> requestParams = request.getParameterMap();
            for (String name : requestParams.keySet()) {
                params.put(name, request.getParameter(name));
                // System.out.println(name + " = " + request.getParameter(name));
            }

            String tradeNo = params.get("out_trade_no");
            String gmtPayment = params.get("gmt_payment");

            // 支付寶驗簽
            if (Factory.Payment.Common().verifyNotify(params)) {
                // 驗簽通過
                System.out.println("交易名稱: " + params.get("subject"));
                System.out.println("交易狀態(tài): " + params.get("trade_status"));
                System.out.println("支付寶交易憑證號: " + params.get("trade_no"));
                System.out.println("商戶訂單號: " + params.get("out_trade_no"));
                System.out.println("交易金額: " + params.get("total_amount"));
                System.out.println("買家在支付寶唯一id: " + params.get("buyer_id"));
                System.out.println("買家付款時間: " + params.get("gmt_payment"));
                System.out.println("買家付款金額: " + params.get("buyer_pay_amount"));

                // 更新訂單未已支付
                orderMapper.updateState(tradeNo, 1, gmtPayment);
            }
        }
        return "success";
    }

@GetMapping("/buy/{bookId}")
    public Result<?> buy(@PathVariable Long bookId) {
        Book book = bookMapper.selectById(bookId);
        String orderNo = IdUtil.getSnowflake().nextIdStr();
        String payUrl = "http://localhost:9090/alipay/pay?subject=" + book.getName() + "&traceNo=" + orderNo + "&totalAmount=" + book.getPrice();

        User user = getUser();
        Order order = new Order();
        order.setOrderNo(orderNo);
        order.setTotalPrice(book.getPrice());
        order.setPayPrice(book.getPrice());
        order.setTransportPrice(BigDecimal.ZERO);
        order.setUserId(user.getId());
        order.setUsername(user.getUsername());
        order.setName(book.getName());
        save(order);
        // 新建訂單，扣減庫存
        return Result.success(payUrl);
    }

buy(bookId) {
      request.get("/order/buy/" + bookId).then(res => {
        // 請求成功跳轉沙箱支付的頁面
        window.open(res.data)
      })
    },