分布式事务 TCC-Transaction 源码分析 —— 项目实战

public class CapitalAccountServiceImpl implements CapitalAccountService {[code]@Autowired
CapitalAccountRepository capitalAccountRepository;

@Override
public BigDecimal getCapitalAccountByUserId(long userId) {
   return capitalAccountRepository.findByUserId(userId).getBalanceAmount();
}

@Autowired
CapitalAccountRepository capitalAccountRepository;

@Override
public BigDecimal getCapitalAccountByUserId(long userId) {
   return capitalAccountRepository.findByUserId(userId).getBalanceAmount();
}

public interface CapitalAccountService {
   BigDecimal getCapitalAccountByUserId(long userId);
}

public interface CapitalTradeOrderService {
   String record(TransactionContext transactionContext, CapitalTradeOrderDto tradeOrderDto);
}

public interface RedPacketAccountService {
   BigDecimal getRedPacketAccountByUserId(long userId);
}

public interface RedPacketTradeOrderService {
   String record(TransactionContext transactionContext, RedPacketTradeOrderDto tradeOrderDto);
}

4. 下单支付流程

@Controller
@RequestMapping("")
public class OrderController {

       @RequestMapping(value = "/placeorder", method = RequestMethod.POST)
   public ModelAndView placeOrder(@RequestParam String redPacketPayAmount,
                                  @RequestParam long shopId,
                                  @RequestParam long payerUserId,
                                  @RequestParam long productId) {
       PlaceOrderRequest request = buildRequest(redPacketPayAmount, shopId, payerUserId, productId);
       // 下单并支付订单
       String merchantOrderNo = placeOrderService.placeOrder(request.getPayerUserId(), request.getShopId(),
               request.getProductQuantities(), request.getRedPacketPayAmount());
       // 返回
       ModelAndView mv = new ModelAndView("pay_success");
       // 查询订单状态
       String status = orderService.getOrderStatusByMerchantOrderNo(merchantOrderNo);
       // 支付结果提示
       String payResultTip = null;
       if ("CONFIRMED".equals(status)) {
           payResultTip = "支付成功";
       } else if ("PAY_FAILED".equals(status)) {
           payResultTip = "支付失败";
       }
       mv.addObject("payResult", payResultTip);
       // 商品信息
       mv.addObject("product", productRepository.findById(productId));
       // 资金账户金额 和 红包账户金额
       mv.addObject("capitalAmount", accountService.getCapitalAccountByUserId(payerUserId));
       mv.addObject("redPacketAmount", accountService.getRedPacketAccountByUserId(payerUserId));
       return mv;
   }

}

PlaceOrderService#placeOrder(...)

OrderService#getOrderStatusByMerchantOrderNo(...)

PlaceOrderService#placeOrder(...)

@Service
public class PlaceOrderServiceImpl {

   public String placeOrder(long payerUserId, long shopId, List<Pair<Long, Integer>> productQuantities, BigDecimal redPacketPayAmount) {
       // 获取商店
       Shop shop = shopRepository.findById(shopId);
       // 创建订单
       Order order = orderService.createOrder(payerUserId, shop.getOwnerUserId(), productQuantities);
       // 发起支付
       Boolean result = false;
       try {
           paymentService.makePayment(order, redPacketPayAmount, order.getTotalAmount().subtract(redPacketPayAmount));
       } catch (ConfirmingException confirmingException) {
           // exception throws with the tcc transaction status is CONFIRMING,
           // when tcc transaction is confirming status,
           // the tcc transaction recovery will try to confirm the whole transaction to ensure eventually consistent.
           result = true;
       } catch (CancellingException cancellingException) {
           // exception throws with the tcc transaction status is CANCELLING,
           // when tcc transaction is under CANCELLING status,
           // the tcc transaction recovery will try to cancel the whole transaction to ensure eventually consistent.
       } catch (Throwable e) {
           // other exceptions throws at TRYING stage.
           // you can retry or cancel the operation.
           e.printStackTrace();
       }
       return order.getMerchantOrderNo();
   }

}

ShopRepository#findById(...)

OrderService#createOrder(...)

"DRAFT"

@Service
public class OrderServiceImpl {[code]@Transactional
public Order createOrder(long payerUserId, long payeeUserId, List<Pair<Long, Integer>> productQuantities) {
   Order order = orderFactory.buildOrder(payerUserId, payeeUserId, productQuantities);
   orderRepository.createOrder(order);
   return order;
}

PaymentService#makePayment(...)

4.1 Try 阶段

PaymentService#makePayment(...)

@Compensable(confirmMethod = "confirmMakePayment", cancelMethod = "cancelMakePayment")
@Transactional
public void makePayment(Order order, BigDecimal redPacketPayAmount, BigDecimal capitalPayAmount) {
  System.out.println("order try make payment called.time seq:" + DateFormatUtils.format(Calendar.getInstance(), "yyyy-MM-dd HH:mm:ss"));
  // 更新订单状态为支付中
  order.pay(redPacketPayAmount, capitalPayAmount);
  orderRepository.updateOrder(order);
  // 资金账户余额支付订单
  String result = tradeOrderServiceProxy.record(null, buildCapitalTradeOrderDto(order));
  // 红包账户余额支付订单
  String result2 = tradeOrderServiceProxy.record(null, buildRedPacketTradeOrderDto(order));
}

confirmMethod

cancelMethod

OrderRepository#updateOrder(...)

// Order.java
public void pay(BigDecimal redPacketPayAmount, BigDecimal capitalPayAmount) {
  this.redPacketPayAmount = redPacketPayAmount;
  this.capitalPayAmount = capitalPayAmount;
  this.status = "PAYING";
}

TradeOrderServiceProxy#record(...)

// TradeOrderServiceProxy.java
@Compensable(propagation = Propagation.SUPPORTS, confirmMethod = "record", cancelMethod = "record", transactionContextEditor = Compensable.DefaultTransactionContextEditor.class)
public String record(TransactionContext transactionContext, CapitalTradeOrderDto tradeOrderDto) {
  return capitalTradeOrderService.record(transactionContext, tradeOrderDto);
}

// CapitalTradeOrderService.java
public interface CapitalTradeOrderService {
   String record(TransactionContext transactionContext, CapitalTradeOrderDto tradeOrderDto);
}

transactionContext

null

transactionContext

propagation=Propagation.SUPPORTS

confirmMethod

cancelMethod

CapitalTradeOrderService#record(...)

TradeOrderServiceProxy#record(...)

CapitalTradeOrderServiceImpl#record(...)

@Override
@Compensable(confirmMethod = "confirmRecord", cancelMethod = "cancelRecord", transactionContextEditor = Compensable.DefaultTransactionContextEditor.class)
@Transactional
public String record(TransactionContext transactionContext, CapitalTradeOrderDto tradeOrderDto) {
  // 调试用
  try {
      Thread.sleep(1000l);
//            Thread.sleep(10000000L);
  } catch (InterruptedException e) {
      throw new RuntimeException(e);
  }
  System.out.println("capital try record called. time seq:" + DateFormatUtils.format(Calendar.getInstance(), "yyyy-MM-dd HH:mm:ss"));
  // 生成交易订单
  TradeOrder tradeOrder = new TradeOrder(
          tradeOrderDto.getSelfUserId(),
          tradeOrderDto.getOppositeUserId(),
          tradeOrderDto.getMerchantOrderNo(),
          tradeOrderDto.getAmount()
  );
  tradeOrderRepository.insert(tradeOrder);
  // 更新减少下单用户的资金账户余额
  CapitalAccount transferFromAccount = capitalAccountRepository.findByUserId(tradeOrderDto.getSelfUserId());
  transferFromAccount.transferFrom(tradeOrderDto.getAmount());
  capitalAccountRepository.save(transferFromAccount);
  return "success";
}

confirmMethod

cancelMethod

TradeOrderRepository#insert(...)

"DRAFT"

CapitalAccountRepository#save(...)

4.2 Confirm / Cancel 阶段

4.2.1 Confirm

PaymentServiceImpl#confirmMakePayment(...)

public void confirmMakePayment(Order order, BigDecimal redPacketPayAmount, BigDecimal capitalPayAmount) {
  // 调试用
  try {
      Thread.sleep(1000l);
  } catch (InterruptedException e) {
      throw new RuntimeException(e);
  }
  System.out.println("order confirm make payment called. time seq:" + DateFormatUtils.format(Calendar.getInstance(), "yyyy-MM-dd HH:mm:ss"));
  // 更新订单状态为支付成功
  order.confirm();
  orderRepository.updateOrder(order);
}

OrderRepository#updateOrder(...)

// Order.java
public void confirm() {
  this.status = "CONFIRMED";
}

CapitalTradeOrderServiceImpl#confirmRecord(...)

@Transactional
public void confirmRecord(TransactionContext transactionContext, CapitalTradeOrderDto tradeOrderDto) {
  // 调试用
  try {
      Thread.sleep(1000l);
  } catch (InterruptedException e) {
      throw new RuntimeException(e);
  }
  System.out.println("capital confirm record called. time seq:" + DateFormatUtils.format(Calendar.getInstance(), "yyyy-MM-dd HH:mm:ss"));
  // 查询交易记录
  TradeOrder tradeOrder = tradeOrderRepository.findByMerchantOrderNo(tradeOrderDto.getMerchantOrderNo());
  // 判断交易记录状态。因为 `#record()` 方法，可能事务回滚，记录不存在 / 状态不对
  if (null != tradeOrder && "DRAFT".equals(tradeOrder.getStatus())) {
      // 更新订单状态为交易成功
      tradeOrder.confirm();
      tradeOrderRepository.update(tradeOrder);
      // 更新增加商店拥有者用户的资金账户余额
      CapitalAccount transferToAccount = capitalAccountRepository.findByUserId(tradeOrderDto.getOppositeUserId());
      transferToAccount.transferTo(tradeOrderDto.getAmount());
      capitalAccountRepository.save(transferToAccount);
  }
}

#record()

TradeOrderRepository#update(...)

CapitalAccountRepository#save(...)

// CapitalAccount.java
public void transferTo(BigDecimal amount) {
  this.balanceAmount = this.balanceAmount.add(amount);
}

4.2.2 Cancel

PaymentServiceImpl#cancelMakePayment(...)

public void cancelMakePayment(Order order, BigDecimal redPacketPayAmount, BigDecimal capitalPayAmount) {
  // 调试用
  try {
      Thread.sleep(1000l);
  } catch (InterruptedException e) {
      throw new RuntimeException(e);
  }
  System.out.println("order cancel make payment called.time seq:" + DateFormatUtils.format(Calendar.getInstance(), "yyyy-MM-dd HH:mm:ss"));
  // 更新订单状态为支付失败
  order.cancelPayment();
  orderRepository.updateOrder(order);
}

OrderRepository#updateOrder(...)

// Order.java
public void cancelPayment() {
   this.status = "PAY_FAILED";
}

CapitalTradeOrderServiceImpl#cancelRecord(...)

@Transactional
public void cancelRecord(TransactionContext transactionContext, CapitalTradeOrderDto tradeOrderDto) {
  // 调试用
  try {
      Thread.sleep(1000l);
  } catch (InterruptedException e) {
      throw new RuntimeException(e);
  }
  System.out.println("capital cancel record called. time seq:" + DateFormatUtils.format(Calendar.getInstance(), "yyyy-MM-dd HH:mm:ss"));
  // 查询交易记录
  TradeOrder tradeOrder = tradeOrderRepository.findByMerchantOrderNo(tradeOrderDto.getMerchantOrderNo());
  // 判断交易记录状态。因为 `#record()` 方法，可能事务回滚，记录不存在 / 状态不对
  if (null != tradeOrder && "DRAFT".equals(tradeOrder.getStatus())) {
      // / 更新订单状态为交易失败
      tradeOrder.cancel();
      tradeOrderRepository.update(tradeOrder);
      // 更新增加( 恢复 )下单用户的资金账户余额
      CapitalAccount capitalAccount = capitalAccountRepository.findByUserId(tradeOrderDto.getSelfUserId());
      capitalAccount.cancelTransfer(tradeOrderDto.getAmount());
      capitalAccountRepository.save(capitalAccount);
  }
}

#record()

TradeOrderRepository#update(...)

CapitalAccountRepository#save(...)

// CapitalAccount.java
public void cancelTransfer(BigDecimal amount) {
   transferTo(amount);
}

666. 彩蛋