【转载】解构领域驱动设计（一）：为什么DDD能够解决软件复杂性

public OrderDto signOrder(Order order) {
    Assert.notNull(order, "OrderDto can not be null.");
    OrderDto result = new OrderDto();
    result.setIsOperationSuccess(true);
    if (null == order.getId()) {
        result.setIsOperationSuccess(false);
        result.setOperationMassage("id不能为空。");
        return result;
    }
    OrderCondition orderCondition = new OrderCondition();
    orderCondition.setId(order.getId());
    order = orderMapper.selectOne(orderCondition);
    if (null == order) {
        result.setIsOperationSuccess(false);
        result.setOperationMassage("该订单不存在。");
        return result;
    }
    if (order.getOrderStatus() != Integer.valueOf(StatusEnum.ORDER_STATUS.ORDER_WAIT_RECEIVE.getCode())) {
        result.setIsOperationSuccess(false);
        result.setOperationMassage("订单号：{" + order.getOrderNo() + "}不是待收货状态，不能进行签收。");
        return result;
    }
    // 该订单下的所有商品的实收数(发货数量)必须都大于0
    boolean validDeliveryCount = true;
    Double orderTotalAmount = 0d;
    List orderGoodsList = orderGoodsBiz.selectOrderGoodsByOrderId(order.getId());
    List orderGoodsListForUpdate = new ArrayList();
    if (EmptyUtil.isNotEmpty(orderGoodsList)) {
        for (OrderGoodsDto orderGoods : orderGoodsList) {
            if (null == orderGoods.getDeliveredNum() || orderGoods.getDeliveredNum() ) {
                validDeliveryCount = false;
            } else {
                // 根据商品发货数量重新计算订单总金额......
                Double price = (null == orderGoods.getDiscountPrice() ? orderGoods.getOriginalPrice() : orderGoods.getDiscountPrice());
                Integer goodsNum = (null == orderGoods.getDeliveredNum() ? 0 : orderGoods.getDeliveredNum());
                orderTotalAmount += price * goodsNum;
                // 更新orderGoods的收货数量
                orderGoods.setReceivedNum(goodsNum);
                OrderGoods orderGoodsForUpdate = new OrderGoods();
                BeanUtils.copyProperties(orderGoods, orderGoodsForUpdate);
                orderGoodsListForUpdate.add(orderGoodsForUpdate);
            }
        }
    }
    if (!validDeliveryCount) {
        result.setIsOperationSuccess(false);
        result.setOperationMassage("订单号：" + order.getOrderNo() + "，订单下所有商品都已发货才可进行签收操作，请确认。");
        return result;
    }
    order.setOrderStatus(Integer.valueOf(StatusEnum.ORDER_STATUS.ORDER_SIGN.getCode()));
    order.setOrderTotalAmount(orderTotalAmount);
    order.setPaymentAmount(orderTotalAmount);
    order.setUnpaidAmount(orderTotalAmount);
    update(order);
    orderGoodsBiz.batchUpdate(orderGoodsListForUpdate);
    List orders = new ArrayList();
    orders.add(order);
    saveRouteMessage(orders);
    return result;
}

public void signOrder(Order order) {
    assertCanBeSigned(order);

    Double orderTotalAmount = 0d;

    List orderGoodsList = order.getOrderGoods();
    for (OrderGoods orderGoods : orderGoodsList) {
        Double price = (null == orderGoods.getDiscountPrice() ? orderGoods.getOriginalPrice() : orderGoods.getDiscountPrice());
        Integer goodsNum = (null == orderGoods.getDeliveredNum() ? 0 : orderGoods.getDeliveredNum());
        orderTotalAmount += price * goodsNum;

        orderGoods.setReceivedNum(goodsNum);
    }

    order.setOrderStatus(Integer.valueOf(StatusEnum.ORDER_STATUS.ORDER_SIGN.getCode()));
    order.setOrderTotalAmount(orderTotalAmount);
    order.setPaymentAmount(orderTotalAmount);
    order.setUnpaidAmount(orderTotalAmount);
}

public void assertCanBeSigned(Order order) {
    Assert.notNull(order, "OrderDto can not be null.");

    if (order.getOrderStatus() != Integer.valueOf(StatusEnum.ORDER_STATUS.ORDER_WAIT_RECEIVE.getCode())) {
        throw new BusinessException("订单号：{" + order.getOrderNo() + "}不是待收货状态，不能进行签收。");
    }

    List orderGoodsList = order.getOrderGoods();
    if (!EmptyUtil.isNotEmpty(orderGoodsList)) {
        throw new BusinessException("订单号：" + order.getOrderNo() + "，订单没有包含商品，是一个空的订单，无法签收。");
    }

    for (OrderGoods orderGoods : orderGoodsList) {
        // 该订单下的所有商品的实收数(发货数量)必须都大于0
        if (null == orderGoods.getDeliveredNum() || orderGoods.getDeliveredNum() ) {
            throw new BusinessException("订单号：" + order.getOrderNo() + "，订单下所有商品都已发货才可进行签收操作，请确认。");
        }
    }
}