entity為了傳遞資訊增加@Transient修飾的屬性會汙染實體純淨

@Entity
@Data
@DynamicUpdate
public class OrderMaster {

    /** 訂單id. */
    @Id
    private String orderId;

    /** 買家名字. */
    private String buyerName;

    /** 買家手機號. */
    private String buyerPhone;

    /** 買家地址. */
    private String buyerAddress;

    /** 買家微信Openid. */
 

    private String buyerOpenid;

    /** 訂單總金額. */
    private BigDecimal orderAmount;

    /** 訂單狀態, 預設為0新下單. */
    private Integer orderStatus = OrderStatusEnum.NEW.getCode();

    /** 支付狀態, 預設為0未支付. */
    private Integer payStatus = PayStatusEnum.WAIT.getCode();

    /** 建立時間. */
    private Date createTime;

    /** 更新時間. */
 

    private Date updateTime;

    @Transient
    private List<OrderDetail> orderDetailList;
}

訂單物件中放入訂單詳情列表會方便傳遞資訊，但造成訂單實體的不純潔，理論上應該和DB欄位一一對應

DTO 資料傳輸物件就是用來解決上面的問題

@Data
public class OrderDTO {

    /** 訂單id. */
    private String orderId;

    /** 買家名字. */
    private String buyerName;

    /** 買家手機號. */
 

    private String buyerPhone;

    /** 買家地址. */
    private String buyerAddress;

    /** 買家微信Openid. */
    private String buyerOpenid;

    /** 訂單總金額. */
    private BigDecimal orderAmount;

    /** 訂單狀態, 預設為0新下單. */
    private Integer orderStatus;

    /** 支付狀態, 預設為0未支付. */
    private Integer payStatus;

    /** 建立時間. */
    @JsonSerialize(using = Date2LongSerializer.class)
    private Date createTime;

    /** 更新時間. */
    @JsonSerialize(using = Date2LongSerializer.class)
    private Date updateTime;

    List<OrderDetail> orderDetailList;

    @JsonIgnore
    public OrderStatusEnum getOrderStatusEnum() {
        return EnumUtil.getByCode(orderStatus, OrderStatusEnum.class);
    }

    @JsonIgnore
    public PayStatusEnum getPayStatusEnum() {
        return EnumUtil.getByCode(payStatus, PayStatusEnum.class);
    }
}

@Data
public class CartDTO {

    /** 商品Id. */
    private String productId;

    /** 數量. */
    private Integer productQuantity;

    public CartDTO(String productId, Integer productQuantity) {
        this.productId = productId;
        this.productQuantity = productQuantity;
    }
}

建立訂單中的dto與entity互動

POST /sell/buyer/order/create

引數
name: "張三"
phone: "18868822111"
address: "慕課網總部"
openid: "ew3euwhd7sjw9diwkq" //使用者的微信openid
items: [{
    productId: "1423113435324",
    productQuantity: 2 //購買數量
}]

@Override
    @Transactional
    public OrderDTO create(OrderDTO orderDTO) {

        String orderId = KeyUtil.genUniqueKey();
        BigDecimal orderAmount = new BigDecimal(BigInteger.ZERO);
        //1. 查詢商品（數量, 價格）
        for (OrderDetail orderDetail: orderDTO.getOrderDetailList()) {
            ProductInfo productInfo =  productService.findOne(orderDetail.getProductId());
            if (productInfo == null) {
                throw new SellException(ResultEnum.PRODUCT_NOT_EXIST);
//                throw new ResponseBankException();
            }

            //2. 計算訂單總價
            orderAmount = productInfo.getProductPrice()
                    .multiply(new BigDecimal(orderDetail.getProductQuantity()))
                    .add(orderAmount);

            //訂單詳情入庫
            orderDetail.setDetailId(KeyUtil.genUniqueKey());
            orderDetail.setOrderId(orderId);
            BeanUtils.copyProperties(productInfo, orderDetail);
            orderDetailRepository.save(orderDetail);

//此處不做扣庫存操作是為了功能純潔
//            CartDTO cartDTO = new CartDTO(orderDetail.getProductId(), orderDetail.getProductQuantity());
//            cartDTOList.add(cartDTO);
        }

        //3. 寫入訂單資料庫（orderMaster和orderDetail）
        OrderMaster orderMaster = new OrderMaster();
        //先在DTO完成賦值，然後再物件拷貝到entity,否則容易覆蓋
        orderDTO.setOrderId(orderId);
        BeanUtils.copyProperties(orderDTO, orderMaster);
        orderMaster.setOrderAmount(orderAmount);
        orderMaster.setOrderStatus(OrderStatusEnum.NEW.getCode());
        orderMaster.setPayStatus(PayStatusEnum.WAIT.getCode());
        orderMasterRepository.save(orderMaster);

        //4. 扣庫存
        List<CartDTO> cartDTOList = orderDTO.getOrderDetailList().stream().map(e ->
                new CartDTO(e.getProductId(), e.getProductQuantity())
        ).collect(Collectors.toList());
        productService.decreaseStock(cartDTOList);

        //傳送websocket訊息
        webSocket.sendMessage(orderDTO.getOrderId());
        return orderDTO;
    }

public class KeyUtil {

    /**
     * 生成唯一的主鍵
     * 格式: 時間+隨機數
     * @return
     */
    public static synchronized String genUniqueKey() {
        Random random = new Random();
        Integer number = random.nextInt(900000) + 100000;
        return System.currentTimeMillis() + String.valueOf(number);
    }
}

訂單分頁列表

  @Override
    public Page<OrderDTO> findList(String buyerOpenid, Pageable pageable) {
        Page<OrderMaster> orderMasterPage = orderMasterRepository.findByBuyerOpenid(buyerOpenid, pageable);

        List<OrderDTO> orderDTOList = OrderMaster2OrderDTOConverter.convert(orderMasterPage.getContent());

        return new PageImpl<OrderDTO>(orderDTOList, pageable, orderMasterPage.getTotalElements());
    }

public class OrderMaster2OrderDTOConverter {

    public static OrderDTO convert(OrderMaster orderMaster) {

        OrderDTO orderDTO = new OrderDTO();
        BeanUtils.copyProperties(orderMaster, orderDTO);
        return orderDTO;
    }

    public static List<OrderDTO> convert(List<OrderMaster> orderMasterList) {
        return orderMasterList.stream().map(e ->
                convert(e)
        ).collect(Collectors.toList());
    }
}