淘东电商项目（60） -聚合支付（集成支付宝）

<dependencies>
    <dependency>
        <groupId>com.alipay.sdk</groupId>
        <artifactId>alipay-sdk-java</artifactId>
        <version>3.7.4.ALL</version>
    </dependency>
</dependencies>

public class AlipayConfig {
//↓↓↓↓↓↓↓↓↓↓请在这里配置您的基本信息↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
  // 应用ID,您的APPID，收款账号既是您的APPID对应支付宝账号
  public static String app_id = "";
  // 商户私钥，您的PKCS8格式RSA2私钥
    public static String merchant_private_key = "";
  // 支付宝公钥,查看地址：https://openhome.alipay.com/platform/keyManage.htm 对应APPID下的支付宝公钥。
    public static String alipay_public_key = "";
  // 服务器异步通知页面路径  需http://格式的完整路径，不能加?id=123这类自定义参数，必须外网可以正常访问
  public static String notify_url = "http://工程公网访问地址/alipay.trade.page.pay-JAVA-UTF-8/notify_url.jsp";
  // 页面跳转同步通知页面路径 需http://格式的完整路径，不能加?id=123这类自定义参数，必须外网可以正常访问
  public static String return_url = "http://工程公网访问地址/alipay.trade.page.pay-JAVA-UTF-8/return_url.jsp";
  // 签名方式
  public static String sign_type = "RSA2";
  // 字符编码格式
  public static String charset = "utf-8";
  // 支付宝网关
  public static String gatewayUrl = "https://openapi.alipay.com/gateway.do";
  // 支付宝网关
  public static String log_path = "C:\\";
//↑↑↑↑↑↑↑↑↑↑请在这里配置您的基本信息↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
    /** 
     * 写日志，方便测试（看网站需求，也可以改成把记录存入数据库）
     * @param sWord 要写入日志里的文本内容
     */
    public static void logResult(String sWord) {
        FileWriter writer = null;
        try {
            writer = new FileWriter(log_path + "alipay_log_" + System.currentTimeMillis()+".txt");
            writer.write(sWord);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (writer != null) {
                try {
                    writer.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

/**
 * description: 支付宝支付渠道
 * create by: YangLinWei
 * create time: 2020/5/13 4:41 下午
 */
@Slf4j
public class AliPayStrategy implements PayStrategy {
  @Override
  public String toPayHtml(PaymentChannelEntity pymentChannel, PayMentTransacDTO payMentTransacDTO) {
    log.info(">>>>>支付宝参数封装开始<<<<<<<<");
    // 获得初始化的AlipayClient
    AlipayClient alipayClient = new DefaultAlipayClient(AlipayConfig.gatewayUrl, AlipayConfig.app_id,
        AlipayConfig.merchant_private_key, "json", AlipayConfig.charset, AlipayConfig.alipay_public_key,
        AlipayConfig.sign_type);
    // 设置请求参数
    AlipayTradePagePayRequest alipayRequest = new AlipayTradePagePayRequest();
    alipayRequest.setReturnUrl(AlipayConfig.return_url);
    alipayRequest.setNotifyUrl(AlipayConfig.notify_url);
    // 商户订单号，商户网站订单系统中唯一订单号，必填
    String outTradeNo = payMentTransacDTO.getPaymentId();
    // 付款金额，必填
    String totalAmount = changeF2Y(payMentTransacDTO.getPayAmount() + "");
    // 订单名称，必填
    String subject = payMentTransacDTO.getProductName();
    // 商品描述，可空
    String body = payMentTransacDTO.getProductName()+"很不错，值得购买！";
    alipayRequest.setBizContent("{\"out_trade_no\":\"" + outTradeNo + "\"," + "\"total_amount\":\"" + totalAmount
        + "\"," + "\"subject\":\"" + subject + "\"," + "\"body\":\"" + body + "\","
        + "\"product_code\":\"FAST_INSTANT_TRADE_PAY\"}");
    // 请求
    try {
      String result = alipayClient.pageExecute(alipayRequest).getBody();
      return result;
    } catch (Exception e) {
      return null;
    }
  }
  /** 金额为分的格式 */
  public static final String CURRENCY_FEN_REGEX = "\\-?[0-9]+";
  /**
   * 将分为单位的转换为元 （除100）
   *
   * @param amount
   * @return
   * @throws Exception
   */
  public static String changeF2Y(String amount) {
    if (!amount.matches(CURRENCY_FEN_REGEX)) {
      return null;
    }
    return BigDecimal.valueOf(Long.valueOf(amount)).divide(new BigDecimal(100)).toString();
  }
}