微服务框架Spring Cloud介绍 Part4: 使用Eureka, Ribbon, Feign实现REST服务客户端

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@Column
@Enumerated(value = EnumType.STRING)
private OrderStatus status;

@OneToMany(fetch = FetchType.LAZY, mappedBy = "order")
private List<OrderItem> orderItemList = new ArrayList<>(0);

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/**
* 下订单
*
* @param placeOrderDto
* @return
*/
@Transactional
public Order placeOrder(PlaceOrderDto placeOrderDto) {

//...

//#1
//查询产品信息
List<Long> productIds = placeOrderDto.getPlaceOrderItemList().stream()
.map(PlaceOrderItemDto::getProductId)
.collect(Collectors.toList());

List<ProductDto> productDtoList = productGateway.findProducts(productIds);

//...

//#2
//查询优惠券信息
List<OrderCoupon> orderCouponList = new ArrayList<>();
Set<Long> couponIdSet = new HashSet<>(placeOrderDto.getCouponIdList());
if (!couponIdSet.isEmpty()) {

//#2
List<CouponDto> couponDtoList = couponGateway.findCoupons(new ArrayList<>(couponIdSet));

orderCouponList = couponDtoList.stream().map(couponDto -> {
OrderCoupon orderCoupon = new OrderCoupon();
orderCoupon.setCouponAmount(couponDto.getAmount());
orderCoupon.setCouponCode(couponDto.getCode());
orderCoupon.setCouponId(couponDto.getId());
return orderCoupon;
}).collect(Collectors.toList());

}

//#3
//计算订单金额
long couponAmount = orderCouponList.stream().mapToLong(OrderCoupon::getCouponAmount).sum();
order.setPayAmount(order.calcPayAmount(order.getTotalAmount(), couponAmount));

//检验账户余额是否足够
if (order.getPayAmount() > 0L) {

boolean balanceEnough = accountGateway.isBalanceEnough(placeOrderDto.getUserId(), order.getPayAmount());
if(!balanceEnough) {
throw new AppBusinessException(CommonErrorCode.BAD_REQUEST, "下单失败, 账户余额不足");
}
}

//...

//#4
eventBus.ask(
AskParameterBuilder.askOptional(askReduceBalance, askUseCoupon)
.callbackClass(OrderCreateCallback.class)
.addParam("orderId", String.valueOf(order.getId()))
.build()
);

return order;
}

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@Transactional
public void markCreateSuccess(Long orderId) {
Order order = checkOrderBeforeMarkSuccessOrFail(orderId);
order.setStatus(OrderStatus.CREATED);

orderRepository.save(order);
}

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boolean balanceEnough = accountGateway.isBalanceEnough(placeOrderDto.getUserId(), order.getPayAmount());

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@Service
public class AccountGateway {

protected Logger logger = LoggerFactory.getLogger(AccountGateway.class);

@Autowired
AccountClient accountClient;

@HystrixCommand(ignoreExceptions = RemoteCallException.class)
public boolean isBalanceEnough(Long userId, Long amount) {
return accountClient.checkEnoughBalance(userId, amount).isSuccess();
}

}

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@FeignClient(AccountUrl.SERVICE_HOSTNAME)
public interface AccountClient {

@RequestMapping(method = RequestMethod.GET, value = AccountUrl.CHECK_ENOUGH_BALANCE)
BooleanWrapper checkEnoughBalance(@PathVariable("userId") Long userId, @RequestParam("balance") Long balance);

}