Because there is no WeChat public number, so learning to pay can not go down.

Tables are related:

create table `product_info`(
    `product_id` varchar(32) not null,
    `product_name` varchar(64) not null comment 'Trade name',
    `product_price` decimal(8,2) not null comment 'Unit Price',
    `product_stock` int not null comment 'Stock',
    `product_description` varchar(64) comment 'describe',
    `product_ico` varchar(512) comment 'Small graph',
    `product_status` tinyint(3) default '0' comment 'Commodity status, 0 normal 1 off shelf'
    `category_type` int not null comment 'Category number',
    `create_time` timestamp not null default current_timestamp comment 'Creation time',
    `update_time` timestamp not null default current_timestamp on update current_timestamp comment 'Modification time',
    primary key(`product_id`)    
)comment 'Commodity list';

# Automatically create time, update time with @DynamicUpdate (on entity class) and jpa

The use of jpa

public interface OrderMasterRepository extends JpaRepository<OrderMaster,String> {
    Page<OrderMaster> findByBuyerOpenid(String buyerOpenid, Pageable pageable);
}

enumeration

Define multiple enumerations as needed. If the order status can be one, the payment status can be one. Do not define all States in one enumeration.

jpa paging

public interface OrderMasterRepository extends JpaRepository<OrderMaster,String> {

    Page<OrderMaster> findByBuyerOpenid(String buyerOpenid, Pageable pageable);
}

controller: Accept page,size:

PageRequest pageRequest = new PageRequest(page,size);
Page<OrderDTO> orderDTOPage = orderService.findList(openid, pageRequest);

DTO

Define DTO delivery in business as needed

Control the length of time for negotiation:

public class Date2LongSerializer  extends JsonSerializer<Date> {
    @Override
    public void serialize(Date date, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
        jsonGenerator.writeNumber(date.getTime()/1000);
    }
}


//Then use it in the transfer class variable.

 @JsonSerialize(using = Date2LongSerializer.class)
 private Date createTime;

//Effect: 3 bits shorter time

Return to json

public class ProductVO {
    @JsonProperty("name")
    private String categoryName;
    @JsonProperty("type")
    private Integer categoryType;
    @JsonProperty("foods")
    private List<ProductInfoVO> productInfoVOList;
}

json The return field is:
name
type
foods

Remove the display for null fields in json

spring:
  jackson:
    default-property-inclusion: non_null

Object copy
Copy the field values in the orderMaster object to the fields in the orderDTO (only the values in variables with the same name are copied)

BeanUtils.copyProperties(orderMaster,orderDTO);

Form validation controller accepts judgment like this

 public ResultVO<Map<String,String>>create(@Valid OrderForm orderForm,
                                              BindingResult bindingResult){
        Map<String,String> map = new HashMap<>();
        if(bindingResult.hasErrors()){
            log.error("[The form parameters are incorrect. orderForm={}",orderForm );
            throw new SellException(ResultEnum.PARAM_ERROR.getCode(),
                    bindingResult.getFieldError().getDefaultMessage());
        }

Lambda expression

  List<Integer> categoryTypeList = productInfoList.stream()
                .map(e -> e.getCategoryType())
                .collect(Collectors.toList());
                

//Traverse the product Info. getCategoryType () in the collection productInfoList through the categoryTypeList