订单初版—2.生单链路中的技术问题说明文档
大纲1.生单链路的业务代码
2.生单链路中可能会出现数据不一致的问题
3.Seata AT模式下的分布式事务的原理
4.Seata AT模式下的分布式事务的读写隔离原理
5.Seata AT模式下的死锁问题以及超时机制
6.Seata AT模式下的读写隔离机制的影响
7.生单链路使用Seata AT模式的具体步骤
8.生单链路使用Seata AT模式时的原理流程
9.生单链路使用Seata AT模式时的并发问题
10.生单链路如何解决库存全局锁争用问题
1.生单链路的业务代码
(1)生成订单流程
(2)入参检查与风控检查
(3)获取商品信息与计算订单价格及验证价格
(4)锁定优惠券与商品库存
(5)新增订单到数据库
(6)发送延迟消息到MQ
(1)生成订单流程
@Service
public class OrderServiceImpl implements OrderService {
...
//提交订单/生成订单接口
@GlobalTransactional(rollbackFor = Exception.class)
@Override
public CreateOrderDTO createOrder(CreateOrderRequest createOrderRequest) {
//1.入参检查
checkCreateOrderRequestParam(createOrderRequest);
//2.风控检查
checkRisk(createOrderRequest);
//3.获取商品信息
List<ProductSkuDTO> productSkuList = listProductSkus(createOrderRequest);
//4.计算订单价格
CalculateOrderAmountDTO calculateOrderAmountDTO = calculateOrderAmount(createOrderRequest, productSkuList);
//5.验证订单实付金额
checkRealPayAmount(createOrderRequest, calculateOrderAmountDTO);
//6.锁定优惠券
lockUserCoupon(createOrderRequest);
//7.锁定商品库存
lockProductStock(createOrderRequest);
//8.生成订单到数据库
addNewOrder(createOrderRequest, productSkuList, calculateOrderAmountDTO);
//9.发送订单延迟消息用于支付超时自动关单
sendPayOrderTimeoutDelayMessage(createOrderRequest);
//返回订单信息
CreateOrderDTO createOrderDTO = new CreateOrderDTO();
createOrderDTO.setOrderId(createOrderRequest.getOrderId());
return createOrderDTO;
}
...
}(2)入参检查与风控检查
@Service
public class OrderServiceImpl implements OrderService {
...
//检查创建订单请求参数
private void checkCreateOrderRequestParam(CreateOrderRequest createOrderRequest) {
ParamCheckUtil.checkObjectNonNull(createOrderRequest);
//订单ID检查
String orderId = createOrderRequest.getOrderId();
ParamCheckUtil.checkStringNonEmpty(orderId, OrderErrorCodeEnum.ORDER_ID_IS_NULL);
//业务线标识检查
Integer businessIdentifier = createOrderRequest.getBusinessIdentifier();
ParamCheckUtil.checkObjectNonNull(businessIdentifier, OrderErrorCodeEnum.BUSINESS_IDENTIFIER_IS_NULL);
if (BusinessIdentifierEnum.getByCode(businessIdentifier) == null) {
throw new OrderBizException(OrderErrorCodeEnum.BUSINESS_IDENTIFIER_ERROR);
}
//用户ID检查
String userId = createOrderRequest.getUserId();
ParamCheckUtil.checkStringNonEmpty(userId, OrderErrorCodeEnum.USER_ID_IS_NULL);
//订单类型检查
Integer orderType = createOrderRequest.getOrderType();
ParamCheckUtil.checkObjectNonNull(businessIdentifier, OrderErrorCodeEnum.ORDER_TYPE_IS_NULL);
if (OrderTypeEnum.getByCode(orderType) == null) {
throw new OrderBizException(OrderErrorCodeEnum.ORDER_TYPE_ERROR);
}
//卖家ID检查
String sellerId = createOrderRequest.getSellerId();
ParamCheckUtil.checkStringNonEmpty(sellerId, OrderErrorCodeEnum.SELLER_ID_IS_NULL);
//配送类型检查
Integer deliveryType = createOrderRequest.getDeliveryType();
ParamCheckUtil.checkObjectNonNull(deliveryType, OrderErrorCodeEnum.USER_ADDRESS_ERROR);
if (DeliveryTypeEnum.getByCode(deliveryType) == null) {
throw new OrderBizException(OrderErrorCodeEnum.DELIVERY_TYPE_ERROR);
}
//地址信息检查
String province = createOrderRequest.getProvince();
String city = createOrderRequest.getCity();
String area = createOrderRequest.getArea();
String streetAddress = createOrderRequest.getStreet();
ParamCheckUtil.checkStringNonEmpty(province, OrderErrorCodeEnum.USER_ADDRESS_ERROR);
ParamCheckUtil.checkStringNonEmpty(city, OrderErrorCodeEnum.USER_ADDRESS_ERROR);
ParamCheckUtil.checkStringNonEmpty(area, OrderErrorCodeEnum.USER_ADDRESS_ERROR);
ParamCheckUtil.checkStringNonEmpty(streetAddress, OrderErrorCodeEnum.USER_ADDRESS_ERROR);
//区域ID检查
String regionId = createOrderRequest.getRegionId();
ParamCheckUtil.checkStringNonEmpty(regionId, OrderErrorCodeEnum.REGION_ID_IS_NULL);
//经纬度检查
BigDecimal lon = createOrderRequest.getLon();
BigDecimal lat = createOrderRequest.getLat();
ParamCheckUtil.checkObjectNonNull(lon, OrderErrorCodeEnum.USER_LOCATION_IS_NULL);
ParamCheckUtil.checkObjectNonNull(lat, OrderErrorCodeEnum.USER_LOCATION_IS_NULL);
//收货人信息检查
String receiverName = createOrderRequest.getReceiverName();
String receiverPhone = createOrderRequest.getReceiverPhone();
ParamCheckUtil.checkStringNonEmpty(receiverName, OrderErrorCodeEnum.ORDER_RECEIVER_IS_NULL);
ParamCheckUtil.checkStringNonEmpty(receiverPhone, OrderErrorCodeEnum.ORDER_RECEIVER_IS_NULL);
//客户端设备信息检查
String clientIp = createOrderRequest.getClientIp();
ParamCheckUtil.checkStringNonEmpty(clientIp, OrderErrorCodeEnum.CLIENT_IP_IS_NULL);
//商品条目信息检查
List<CreateOrderRequest.OrderItemRequest> orderItemRequestList = createOrderRequest.getOrderItemRequestList();
ParamCheckUtil.checkCollectionNonEmpty(orderItemRequestList, OrderErrorCodeEnum.ORDER_ITEM_IS_NULL);
for (CreateOrderRequest.OrderItemRequest orderItemRequest : orderItemRequestList) {
Integer productType = orderItemRequest.getProductType();
Integer saleQuantity = orderItemRequest.getSaleQuantity();
String skuCode = orderItemRequest.getSkuCode();
ParamCheckUtil.checkObjectNonNull(productType, OrderErrorCodeEnum.ORDER_ITEM_PARAM_ERROR);
ParamCheckUtil.checkObjectNonNull(saleQuantity, OrderErrorCodeEnum.ORDER_ITEM_PARAM_ERROR);
ParamCheckUtil.checkStringNonEmpty(skuCode, OrderErrorCodeEnum.ORDER_ITEM_PARAM_ERROR);
}
//订单费用信息检查
List<CreateOrderRequest.OrderAmountRequest> orderAmountRequestList = createOrderRequest.getOrderAmountRequestList();
ParamCheckUtil.checkCollectionNonEmpty(orderAmountRequestList, OrderErrorCodeEnum.ORDER_AMOUNT_IS_NULL);
for (CreateOrderRequest.OrderAmountRequest orderAmountRequest : orderAmountRequestList) {
Integer amountType = orderAmountRequest.getAmountType();
ParamCheckUtil.checkObjectNonNull(amountType, OrderErrorCodeEnum.ORDER_AMOUNT_TYPE_IS_NULL);
if (AmountTypeEnum.getByCode(amountType) == null) {
throw new OrderBizException(OrderErrorCodeEnum.ORDER_AMOUNT_TYPE_PARAM_ERROR);
}
}
Map<Integer, Integer> orderAmountMap = orderAmountRequestList.stream()
.collect(Collectors.toMap(CreateOrderRequest.OrderAmountRequest::getAmountType, CreateOrderRequest.OrderAmountRequest::getAmount));
//订单支付原价不能为空
if (orderAmountMap.get(AmountTypeEnum.ORIGIN_PAY_AMOUNT.getCode()) == null) {
throw new OrderBizException(OrderErrorCodeEnum.ORDER_ORIGIN_PAY_AMOUNT_IS_NULL);
}
//订单运费不能为空
if (orderAmountMap.get(AmountTypeEnum.SHIPPING_AMOUNT.getCode()) == null) {
throw new OrderBizException(OrderErrorCodeEnum.ORDER_SHIPPING_AMOUNT_IS_NULL);
}
//订单实付金额不能为空
if (orderAmountMap.get(AmountTypeEnum.REAL_PAY_AMOUNT.getCode()) == null) {
throw new OrderBizException(OrderErrorCodeEnum.ORDER_REAL_PAY_AMOUNT_IS_NULL);
}
if (StringUtils.isNotEmpty(createOrderRequest.getCouponId())) {
//订单优惠券抵扣金额不能为空
if (orderAmountMap.get(AmountTypeEnum.COUPON_DISCOUNT_AMOUNT.getCode()) == null) {
throw new OrderBizException(OrderErrorCodeEnum.ORDER_DISCOUNT_AMOUNT_IS_NULL);
}
}
//订单支付信息检查
List<CreateOrderRequest.PaymentRequest> paymentRequestList = createOrderRequest.getPaymentRequestList();
ParamCheckUtil.checkCollectionNonEmpty(paymentRequestList, OrderErrorCodeEnum.ORDER_PAYMENT_IS_NULL);
for (CreateOrderRequest.PaymentRequest paymentRequest : paymentRequestList) {
Integer payType = paymentRequest.getPayType();
Integer accountType = paymentRequest.getAccountType();
if (payType == null || PayTypeEnum.getByCode(payType) == null) {
throw new OrderBizException(OrderErrorCodeEnum.PAY_TYPE_PARAM_ERROR);
}
if (accountType == null || AccountTypeEnum.getByCode(accountType) == null) {
throw new OrderBizException(OrderErrorCodeEnum.ACCOUNT_TYPE_PARAM_ERROR);
}
}
}
//风控检查
private void checkRisk(CreateOrderRequest createOrderRequest) {
//调用风控服务进行风控检查
CheckOrderRiskRequest checkOrderRiskRequest = createOrderRequest.clone(CheckOrderRiskRequest.class);
JsonResult<CheckOrderRiskDTO> jsonResult = riskApi.checkOrderRisk(checkOrderRiskRequest);
if (!jsonResult.getSuccess()) {
throw new OrderBizException(jsonResult.getErrorCode(), jsonResult.getErrorMessage());
}
}
...
}(3)获取商品信息与计算订单价格及验证价格
@Service
public class OrderServiceImpl implements OrderService {
...
//获取订单条目商品信息
private List<ProductSkuDTO> listProductSkus(CreateOrderRequest createOrderRequest) {
List<CreateOrderRequest.OrderItemRequest> orderItemRequestList = createOrderRequest.getOrderItemRequestList();
List<ProductSkuDTO> productSkuList = new ArrayList<>();
for (CreateOrderRequest.OrderItemRequest orderItemRequest : orderItemRequestList) {
String skuCode = orderItemRequest.getSkuCode();
ProductSkuQuery productSkuQuery = new ProductSkuQuery();
productSkuQuery.setSkuCode(skuCode);
productSkuQuery.setSellerId(createOrderRequest.getSellerId());
JsonResult<ProductSkuDTO> jsonResult = productApi.getProductSku(productSkuQuery);
if (!jsonResult.getSuccess()) {
throw new OrderBizException(jsonResult.getErrorCode(), jsonResult.getErrorMessage());
}
ProductSkuDTO productSkuDTO = jsonResult.getData();
//sku不存在
if (productSkuDTO == null) {
throw new OrderBizException(OrderErrorCodeEnum.PRODUCT_SKU_CODE_ERROR, skuCode);
}
productSkuList.add(productSkuDTO);
}
return productSkuList;
}
//计算订单价格，如果使用了优惠券、红包、积分等，会一并进行扣减
//@param createOrderRequest 订单信息
//@param productSkuList 商品信息
private CalculateOrderAmountDTO calculateOrderAmount(CreateOrderRequest createOrderRequest, List<ProductSkuDTO> productSkuList) {
CalculateOrderAmountRequest calculateOrderPriceRequest = createOrderRequest.clone(CalculateOrderAmountRequest.class, CloneDirection.FORWARD);
//订单条目补充商品信息
Map<String, ProductSkuDTO> productSkuDTOMap = productSkuList.stream().collect(Collectors.toMap(ProductSkuDTO::getSkuCode, Function.identity()));
calculateOrderPriceRequest.getOrderItemRequestList().forEach(item -> {
String skuCode = item.getSkuCode();
ProductSkuDTO productSkuDTO = productSkuDTOMap.get(skuCode);
item.setProductId(productSkuDTO.getProductId());
item.setSalePrice(productSkuDTO.getSalePrice());
});
//调用营销服务计算订单价格
JsonResult<CalculateOrderAmountDTO> jsonResult = marketApi.calculateOrderAmount(calculateOrderPriceRequest);
//检查价格计算结果
if (!jsonResult.getSuccess()) {
throw new OrderBizException(jsonResult.getErrorCode(), jsonResult.getErrorMessage());
}
CalculateOrderAmountDTO calculateOrderAmountDTO = jsonResult.getData();
if (calculateOrderAmountDTO == null) {
throw new OrderBizException(OrderErrorCodeEnum.CALCULATE_ORDER_AMOUNT_ERROR);
}
//订单费用信息
List<OrderAmountDTO> orderAmountList = ObjectUtil.convertList(calculateOrderAmountDTO.getOrderAmountList(), OrderAmountDTO.class);
if (orderAmountList == null || orderAmountList.isEmpty()) {
throw new OrderBizException(OrderErrorCodeEnum.CALCULATE_ORDER_AMOUNT_ERROR);
}
//订单条目费用明细
List<OrderAmountDetailDTO> orderItemAmountList = ObjectUtil.convertList(calculateOrderAmountDTO.getOrderAmountDetail(), OrderAmountDetailDTO.class);
if (orderItemAmountList == null || orderItemAmountList.isEmpty()) {
throw new OrderBizException(OrderErrorCodeEnum.CALCULATE_ORDER_AMOUNT_ERROR);
}
return calculateOrderAmountDTO;
}
//验证订单实付金额
private void checkRealPayAmount(CreateOrderRequest createOrderRequest, CalculateOrderAmountDTO calculateOrderAmountDTO) {
List<CreateOrderRequest.OrderAmountRequest> originOrderAmountRequestList = createOrderRequest.getOrderAmountRequestList();
Map<Integer, CreateOrderRequest.OrderAmountRequest> originOrderAmountMap =
originOrderAmountRequestList.stream().collect(Collectors.toMap(CreateOrderRequest.OrderAmountRequest::getAmountType, Function.identity()));
//前端给的实付金额
Integer originRealPayAmount = originOrderAmountMap.get(AmountTypeEnum.REAL_PAY_AMOUNT.getCode()).getAmount();
List<CalculateOrderAmountDTO.OrderAmountDTO> orderAmountDTOList = calculateOrderAmountDTO.getOrderAmountList();
Map<Integer, CalculateOrderAmountDTO.OrderAmountDTO> orderAmountMap =
orderAmountDTOList.stream().collect(Collectors.toMap(CalculateOrderAmountDTO.OrderAmountDTO::getAmountType, Function.identity()));
//营销计算出来的实付金额
Integer realPayAmount = orderAmountMap.get(AmountTypeEnum.REAL_PAY_AMOUNT.getCode()).getAmount();
if (!originRealPayAmount.equals(realPayAmount)) {
//订单验价失败
throw new OrderBizException(OrderErrorCodeEnum.ORDER_CHECK_REAL_PAY_AMOUNT_FAIL);
}
}
...
}(4)锁定优惠券与商品库存
@Service
public class OrderServiceImpl implements OrderService {
...
//锁定用户优惠券
private void lockUserCoupon(CreateOrderRequest createOrderRequest) {
String couponId = createOrderRequest.getCouponId();
if (StringUtils.isEmpty(couponId)) {
return;
}
LockUserCouponRequest lockUserCouponRequest = createOrderRequest.clone(LockUserCouponRequest.class);
//调用营销服务锁定用户优惠券
JsonResult<Boolean> jsonResult = marketApi.lockUserCoupon(lockUserCouponRequest);
//检查锁定用户优惠券结果
if (!jsonResult.getSuccess()) {
throw new OrderBizException(jsonResult.getErrorCode(), jsonResult.getErrorMessage());
}
}
//锁定商品库存
private void lockProductStock(CreateOrderRequest createOrderRequest) {
String orderId = createOrderRequest.getOrderId();
List<LockProductStockRequest.OrderItemRequest> orderItemRequestList = ObjectUtil.convertList(
createOrderRequest.getOrderItemRequestList(), LockProductStockRequest.OrderItemRequest.class);
LockProductStockRequest lockProductStockRequest = new LockProductStockRequest();
lockProductStockRequest.setOrderId(orderId);
lockProductStockRequest.setOrderItemRequestList(orderItemRequestList);
JsonResult<Boolean> jsonResult = inventoryApi.lockProductStock(lockProductStockRequest);
//检查锁定商品库存结果
if (!jsonResult.getSuccess()) {
throw new OrderBizException(jsonResult.getErrorCode(), jsonResult.getErrorMessage());
}
}
...
}
@DubboService(version = "1.0.0", interfaceClass = MarketApi.class, retries = 0)
public class MarketApiImpl implements MarketApi {
...
//锁定用户优惠券记录
@Override
public JsonResult<Boolean> lockUserCoupon(LockUserCouponRequest lockUserCouponRequest) {
try {
Boolean result = couponService.lockUserCoupon(lockUserCouponRequest);
return JsonResult.buildSuccess(result);
} catch (MarketBizException e) {
log.error("biz error", e);
return JsonResult.buildError(e.getErrorCode(), e.getErrorMsg());
} catch (Exception e) {
log.error("system error", e);
return JsonResult.buildError(e.getMessage());
}
}
...
}
@Service
public class CouponServiceImpl implements CouponService {
...
//锁定用户优惠券
@Transactional(rollbackFor = Exception.class)
@Override
public Boolean lockUserCoupon(LockUserCouponRequest lockUserCouponRequest) {
//检查入参
checkLockUserCouponRequest(lockUserCouponRequest);
String userId = lockUserCouponRequest.getUserId();
String couponId = lockUserCouponRequest.getCouponId();
CouponDO couponDO = couponDAO.getUserCoupon(userId, couponId);
if (couponDO == null) {
throw new MarketBizException(MarketErrorCodeEnum.USER_COUPON_IS_NULL);
}
//判断优惠券是否已经使用了
if (CouponUsedStatusEnum.USED.getCode().equals(couponDO.getUsed())) {
throw new MarketBizException(MarketErrorCodeEnum.USER_COUPON_IS_USED);
}
couponDO.setUsed(CouponUsedStatusEnum.USED.getCode());
couponDO.setUsedTime(new Date());
couponDAO.updateById(couponDO);
return true;
}
...
}
@DubboService(version = "1.0.0", interfaceClass = InventoryApi.class, retries = 0)
public class InventoryApiImpl implements InventoryApi {
@Autowired
private InventoryService inventoryService;
//锁定商品库存
@Override
public JsonResult<Boolean> lockProductStock(LockProductStockRequest lockProductStockRequest) {
try {
Boolean result = inventoryService.lockProductStock(lockProductStockRequest);
return JsonResult.buildSuccess(result);
} catch (InventoryBizException e) {
log.error("biz error", e);
return JsonResult.buildError(e.getErrorCode(), e.getErrorMsg());
} catch (Exception e) {
log.error("system error", e);
return JsonResult.buildError(e.getMessage());
}
}
...
}
@Service
public class InventoryServiceImpl implements InventoryService {
...
//锁定商品库存
@Transactional(rollbackFor = Exception.class)
@Override
public Boolean lockProductStock(LockProductStockRequest lockProductStockRequest) {
//检查入参
checkLockProductStockRequest(lockProductStockRequest);
List<LockProductStockRequest.OrderItemRequest> orderItemRequestList = lockProductStockRequest.getOrderItemRequestList();
for (LockProductStockRequest.OrderItemRequest orderItemRequest : orderItemRequestList) {
String skuCode = orderItemRequest.getSkuCode();
ProductStockDO productStockDO = productStockDAO.getBySkuCode(skuCode);
if (productStockDO == null) {
throw new InventoryBizException(InventoryErrorCodeEnum.PRODUCT_SKU_STOCK_ERROR);
}
Integer saleQuantity = orderItemRequest.getSaleQuantity();
//执行库存扣减，并需要解决防止超卖的问题
int nums = productStockDAO.lockProductStock(skuCode, saleQuantity);
if (nums <= 0) {
throw new InventoryBizException(InventoryErrorCodeEnum.LOCK_PRODUCT_SKU_STOCK_ERROR);
}
}
return true;
}
...
}(6)发送延迟消息到MQ
@Service
public class OrderServiceImpl implements OrderService {
...
//新增订单数据到数据库
private void addNewOrder(CreateOrderRequest createOrderRequest, List<ProductSkuDTO> productSkuList, CalculateOrderAmountDTO calculateOrderAmountDTO) {
//封装新订单数据
NewOrderDataHolder newOrderDataHolder = new NewOrderDataHolder();
//生成主订单
FullOrderData fullMasterOrderData = addNewMasterOrder(createOrderRequest, productSkuList, calculateOrderAmountDTO);
//封装主订单数据到NewOrderData对象中
newOrderDataHolder.appendOrderData(fullMasterOrderData);
//如果存在多种商品类型，需要按商品类型进行拆单
Map<Integer, List<ProductSkuDTO>> productTypeMap = productSkuList.stream().collect(Collectors.groupingBy(ProductSkuDTO::getProductType));
if (productTypeMap.keySet().size() > 1) {
for (Integer productType : productTypeMap.keySet()) {
//生成子订单
FullOrderData fullSubOrderData = addNewSubOrder(fullMasterOrderData, productType);
//封装子订单数据到NewOrderData对象中
newOrderDataHolder.appendOrderData(fullSubOrderData);
}
}
//保存订单到数据库
//订单信息
List<OrderInfoDO> orderInfoDOList = newOrderDataHolder.getOrderInfoDOList();
if (!orderInfoDOList.isEmpty()) {
orderInfoDAO.saveBatch(orderInfoDOList);
}
//订单条目
List<OrderItemDO> orderItemDOList = newOrderDataHolder.getOrderItemDOList();
if (!orderItemDOList.isEmpty()) {
orderItemDAO.saveBatch(orderItemDOList);
}
//订单配送信息
List<OrderDeliveryDetailDO> orderDeliveryDetailDOList = newOrderDataHolder.getOrderDeliveryDetailDOList();
if (!orderDeliveryDetailDOList.isEmpty()) {
orderDeliveryDetailDAO.saveBatch(orderDeliveryDetailDOList);
}
//订单支付信息
List<OrderPaymentDetailDO> orderPaymentDetailDOList = newOrderDataHolder.getOrderPaymentDetailDOList();
if (!orderPaymentDetailDOList.isEmpty()) {
orderPaymentDetailDAO.saveBatch(orderPaymentDetailDOList);
}
//订单费用信息
List<OrderAmountDO> orderAmountDOList = newOrderDataHolder.getOrderAmountDOList();
if (!orderAmountDOList.isEmpty()) {
orderAmountDAO.saveBatch(orderAmountDOList);
}
//订单费用明细
List<OrderAmountDetailDO> orderAmountDetailDOList = newOrderDataHolder.getOrderAmountDetailDOList();
if (!orderAmountDetailDOList.isEmpty()) {
orderAmountDetailDAO.saveBatch(orderAmountDetailDOList);
}
//订单状态变更日志信息
List<OrderOperateLogDO> orderOperateLogDOList = newOrderDataHolder.getOrderOperateLogDOList();
if (!orderOperateLogDOList.isEmpty()) {
orderOperateLogDAO.saveBatch(orderOperateLogDOList);
}
//订单快照数据
List<OrderSnapshotDO> orderSnapshotDOList = newOrderDataHolder.getOrderSnapshotDOList();
if (!orderSnapshotDOList.isEmpty()) {
orderSnapshotDAO.saveBatch(orderSnapshotDOList);
}
}
//新增主订单信息订单
private FullOrderData addNewMasterOrder(CreateOrderRequest createOrderRequest, List<ProductSkuDTO> productSkuList, CalculateOrderAmountDTO calculateOrderAmountDTO) {
NewOrderBuilder newOrderBuilder = new NewOrderBuilder(createOrderRequest, productSkuList, calculateOrderAmountDTO, orderProperties);
FullOrderData fullOrderData = newOrderBuilder.buildOrder()
.buildOrderItems()
.buildOrderDeliveryDetail()
.buildOrderPaymentDetail()
.buildOrderAmount()
.buildOrderAmountDetail()
.buildOperateLog()
.buildOrderSnapshot()
.build();
//订单信息
OrderInfoDO orderInfoDO = fullOrderData.getOrderInfoDO();
//订单条目信息
List<OrderItemDO> orderItemDOList = fullOrderData.getOrderItemDOList();
//订单费用信息
List<OrderAmountDO> orderAmountDOList = fullOrderData.getOrderAmountDOList();
//补全地址信息
OrderDeliveryDetailDO orderDeliveryDetailDO = fullOrderData.getOrderDeliveryDetailDO();
String detailAddress = getDetailAddress(orderDeliveryDetailDO);
orderDeliveryDetailDO.setDetailAddress(detailAddress);
//补全订单状态变更日志
OrderOperateLogDO orderOperateLogDO = fullOrderData.getOrderOperateLogDO();
String remark = "创建订单操作0-10";
orderOperateLogDO.setRemark(remark);
//补全订单商品快照信息
List<OrderSnapshotDO> orderSnapshotDOList = fullOrderData.getOrderSnapshotDOList();
for (OrderSnapshotDO orderSnapshotDO : orderSnapshotDOList) {
//优惠券信息
if (orderSnapshotDO.getSnapshotType().equals(SnapshotTypeEnum.ORDER_COUPON.getCode())) {
...
}
//订单费用信息
else if (orderSnapshotDO.getSnapshotType().equals(SnapshotTypeEnum.ORDER_AMOUNT.getCode())) {
orderSnapshotDO.setSnapshotJson(JsonUtil.object2Json(orderAmountDOList));
}
//订单条目信息
else if (orderSnapshotDO.getSnapshotType().equals(SnapshotTypeEnum.ORDER_ITEM.getCode())) {
orderSnapshotDO.setSnapshotJson(JsonUtil.object2Json(orderItemDOList));
}
}
return fullOrderData;
}
...
}
2.生单链路中可能会出现数据不一致的问题
在更新优惠券本地事务、更新库存本地事务、插入订单数据本地事务中，可能会出现优惠券和库存都已经更新成功了，但订单数据却插入失败，此时就会出现数据不一致的问题。
3.Seata AT模式下的分布式事务的原理
说明一：需要部署一个Seata Server服务器。
说明二：在各个服务的分支事务的数据库中，需要新增一张undo_log表，用来记录各个服务的分支事务失败时可以执行的回滚SQL。
说明三：当入口服务开启一个分布式事务时，需要向Seata Server开启一个全局事务。
说明四：各个服务对其分支事务的执行情况会同步给Seata Server服务器。
说明五：当Seata Server发现某分支事务失败时，便会通知各服务进行事务回滚。
说明六：当各个服务进行事务回滚时，会从undo_log表查出对应SQL去执行。
4.Seata AT模式下的分布式事务的读写隔离原理
为了避免有其他线程修改某数据后又进行回滚，就一定要加本地锁 + 全局锁。本地锁是为了避免当前机器的其他线程对数据进行修改并回滚，全局锁是为了避免分布式机器的线程对数据进行修改并回滚。
服务A在更新某数据之前，需要先获取本地锁。服务A在成功获取本地锁之后，需要插入undo log数据。接着，服务A需要向Seata Server服务器获取全局锁。服务A在成功获取全局锁之后，会提交本地事务并释放本地锁。
如果服务A对服务B进行RPC调用并提交其本地事务，则继续按前面的步骤处理服务B的数据更新。当服务B的本地事务也提交完成后，不需要继续执行其他分支事务了，服务A便可以提交分布式事务，并释放全局锁。
分布式事务的全链路在执行完毕前，对应数据的全局锁是不会释放的。
5.Seata AT模式下的死锁问题以及超时机制
Seata的一条事务链路里，每一个事务都会按如下顺序执行：首先获取本地锁更新本地数据，然后插入undo log记录，接着获取本地数据对应的全局锁，最后提交本地事务并释放本地锁。
Seata的一条事务链路里，一个事务执行完就会继续执行下一个事务。如果事务链路里的所有事务都执行完成了，那么就提交事务，并释放全局锁。如果某个事务需要回滚，那么就需要获取该事务本地数据的本地锁，然后获取undo log记录生成逆向操作的SQL语句来进行补偿和更新，补偿完毕才能释放本地数据的全局锁。
由于Seata AT模式的写隔离是通过本地数据的全局锁来实现的，所以写隔离的过程中，就涉及到了本地数据的本地锁和全局锁两把锁，这时候就很容易导致出现死锁的情况。
比如当事务1的分支事务提交数据1的本地事务后，会释放数据1的本地锁。此时事务2的分支事务就可以获取数据1的本地锁，但要等待获取事务1释放数据1的全局锁后，才能释放数据1的本地锁。如果事务1的后续分支事务出现异常需要进行回滚，那么事务1就需要获取数据1的本地锁，执行回滚补偿处理。事务1执行完分支事务的回滚补偿处理后，才能释放数据1的全局锁。
于是就出现了这样的死锁场景：事务1对数据1的回滚，占用了数据1的全局锁，需等待获取数据1的本地锁。事务2对数据1的更新，占用了数据1的本地锁，需等待获取数据1的全局锁。
Seata为了解决这个问题，会引入等待全局锁的超时机制。如果事务2在等待数据1的全局锁时出现超时，就会释放其占用的本地锁。从而让事务1能获取到数据1的本地锁，完成其事务操作，而不用一直等待。
6.Seata AT模式下的读写隔离机制的影响
由于全局锁的存在，会严重影响Seata AT分布式事务的并发吞吐量。所以除非是金融级别的系统，才会使用像Seata AT模式这么严格的事务来保证数据的强一致性。
当然，通常情况下分布式事务基本都是更新不同的数据。只要更新不同的数据，那么Seata AT分布式事务也不会出现全局锁等待。只有一些特殊情况下，才可能会出现大量分布式事务更新同一条数据。当使用Seata AT分布式事务时，特别注意尽量不要让全局锁等待。
如果不使用全局锁，那么Seata AT模式的分布式事务就会出现写未提交。就可能出现分支事务更新失败时无法回滚，因为回滚的数据已被覆盖。
Seata AT模式的分布式事务默认是读未提交的，即分布式事务在未提交前，分支事务更新的数据是可被其他事务读到的。
此外，很多公司都是使用基于RocketMQ的柔性事务来实现分布式事务。
7.生单链路使用Seata AT模式的具体步骤
(1)生单链路中分布式事务的主要分支事务
(2)订单系统 + 优惠券系统 + 商品库存系统都需要在pom.xml文件中引入Seata
(3)订单系统的生单接口作为分布式事务入口需添加@GlobalTransactional注解开启全局事务
(4)优惠券系统的锁定优惠券接口需添加Spring的事务注解@Transactional
(5)商品库存系统的锁定库存接口需添加Spring的事务注解@Transactional
(6)各分支事务操作的数据库需要添加undo log表
(1)生单链路中分布式事务的主要分支事务
分布式事务入口：订单系统的生单接口
分支事务1：优惠券系统锁定优惠券
分支事务2：商品库存系统锁定商品库存
分支事务3：订单系统创建订单数据
(2)订单系统 + 优惠券系统 + 商品库存系统都需要在pom.xml文件中引入Seata
@Service
public class OrderServiceImpl implements OrderService {
...
//发送支付订单超时延迟消息，用于支付超时自动关单
private void sendPayOrderTimeoutDelayMessage(CreateOrderRequest createOrderRequest) {
PayOrderTimeoutDelayMessage message = new PayOrderTimeoutDelayMessage();
message.setOrderId(createOrderRequest.getOrderId());
message.setBusinessIdentifier(createOrderRequest.getBusinessIdentifier());
message.setCancelType(OrderCancelTypeEnum.TIMEOUT_CANCELED.getCode());
message.setUserId(createOrderRequest.getUserId());
message.setOrderType(createOrderRequest.getOrderType());
message.setOrderStatus(OrderStatusEnum.CREATED.getCode());
String msgJson = JsonUtil.object2Json(message);
defaultProducer.sendMessage(
RocketMqConstant.PAY_ORDER_TIMEOUT_DELAY_TOPIC,
msgJson,
RocketDelayedLevel.DELAYED_30m,
"支付订单超时延迟消息"
);
}
...
}
@Component
public class DefaultProducer {
private final DefaultMQProducer producer;
@Autowired
public DefaultProducer(RocketMQProperties rocketMQProperties) {
producer = new DefaultMQProducer(RocketMqConstant.ORDER_DEFAULT_PRODUCER_GROUP);
producer.setNamesrvAddr(rocketMQProperties.getNameServer());
start();
}
//对象在使用之前必须要调用一次，只能初始化一次
public void start() {
try {
this.producer.start();
} catch (MQClientException e) {
log.error("producer start error", e);
}
}
...
//发送消息
public void sendMessage(String topic, String message, Integer delayTimeLevel, String type) {
Message msg = new Message(topic, message.getBytes(StandardCharsets.UTF_8));
try {
if (delayTimeLevel > 0) {
msg.setDelayTimeLevel(delayTimeLevel);
}
SendResult send = producer.send(msg);
if (SendStatus.SEND_OK == send.getSendStatus()) {
log.info("发送MQ消息成功, type:{}, message:{}", type, message);
} else {
throw new OrderBizException(send.getSendStatus().toString());
}
} catch (Exception e) {
log.error("发送MQ消息失败：", e);
throw new OrderBizException(OrderErrorCodeEnum.SEND_MQ_FAILED);
}
}
...
}(3)订单系统的生单接口作为分布式事务入口需添加@GlobalTransactional注解开启全局事务
通过添加Seata提供的注解@GlobalTransactional来开启全局事务。
<dependency>
<groupId>com.alibaba.cloud</groupId>
spring-cloud-starter-alibaba-seata</artifactId>
<exclusions>
<exclusion>
<groupId>io.seata</groupId>
seata-spring-boot-starter</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>io.seata</groupId>
seata-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>(4)优惠券系统的锁定优惠券接口需添加Spring的事务注解@Transactional
通过添加Spring提供的@Transactional注解来开启本地事务。Seata会代理Spring的事务，进行本地锁申请 + undo log写入 + 全局锁请求 + 提交/回滚本地事务等操作。
@Service
public class OrderServiceImpl implements OrderService {
...
//提交订单/生成订单接口
//@param createOrderRequest 提交订单请求入参
//@return 订单号
@GlobalTransactional(rollbackFor = Exception.class)
@Override
public CreateOrderDTO createOrder(CreateOrderRequest createOrderRequest) {
//1.入参检查
checkCreateOrderRequestParam(createOrderRequest);
//2.风控检查
checkRisk(createOrderRequest);
//3.获取商品信息
List<ProductSkuDTO> productSkuList = listProductSkus(createOrderRequest);
//4.计算订单价格
CalculateOrderAmountDTO calculateOrderAmountDTO = calculateOrderAmount(createOrderRequest, productSkuList);
//5.验证订单实付金额
checkRealPayAmount(createOrderRequest, calculateOrderAmountDTO);
//6.锁定优惠券
lockUserCoupon(createOrderRequest);
//7.锁定商品库存
lockProductStock(createOrderRequest);
//8.生成订单到数据库
addNewOrder(createOrderRequest, productSkuList, calculateOrderAmountDTO);
//9.发送订单延迟消息用于支付超时自动关单
sendPayOrderTimeoutDelayMessage(createOrderRequest);
//返回订单信息
CreateOrderDTO createOrderDTO = new CreateOrderDTO();
createOrderDTO.setOrderId(createOrderRequest.getOrderId());
return createOrderDTO;
}
...
}(5)商品库存系统的锁定库存接口需添加Spring的事务注解@Transactional
通过添加Spring提供的@Transactional注解来开启本地事务。Seata会代理Spring的事务，进行本地锁申请 + undo log写入 + 全局锁请求 + 提交/回滚本地事务等操作。
@Servicepublic class InventoryServiceImpl implements InventoryService { ... //锁定商品库存 @Transactional(rollbackFor = Exception.class) @Override public Boolean lockProductStock(LockProductStockRequest lockProductStockRequest) { //检查入参 checkLockProductStockRequest(lockProductStockRequest); List orderItemRequestList = lockProductStockRequest.getOrderItemRequestList(); for (LockProductStockRequest.OrderItemRequest orderItemRequest : orderItemRequestList) { String skuCode = orderItemRequest.getSkuCode(); ProductStockDO productStockDO = productStockDAO.getBySkuCode(skuCode); if (productStockDO == null) { throw new InventoryBizException(InventoryErrorCodeEnum.PRODUCT_SKU_STOCK_ERROR); } Integer saleQuantity = orderItemRequest.getSaleQuantity(); //执行库存扣减，并需要解决防止超卖的问题 int nums = productStockDAO.lockProductStock(skuCode, saleQuantity); if (nums 懂技术并乐意极积无私分享的人越来越少。珍惜 谢谢楼主提供！ 前排留名，哈哈哈 这个好，看起来很实用 鼓励转贴优秀软件安全工具和文档！ 热心回复！ 这个好，看起来很实用 这个好，看起来很实用 感谢分享 感谢，下载保存了 收藏一下 不知道什么时候能用到 感谢，下载保存了 分享、互助 让互联网精神温暖你我 收藏一下 不知道什么时候能用到 喜欢鼓捣这些软件，现在用得少，谢谢分享！ yyds。多谢分享 东西不错很实用谢谢分享 感谢分享，下载保存了，貌似很强大 热心回复！
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