学习笔记

新建表

create table if not exists order_info (    id varchar(32) not null default '',    user_id int not null default 0,    item_id int not null default 0,    item_price double(10, 2) not null default 0,    amount int not null default 0,    order_price double(10, 2) default 0,    primary key (id));create table if not exists sequence_info (    name varchar(64) not null default '',    current_value int not null default 0,    step int not null default 1,    primary key (name));insert into sequence_info (name, current_value, step) values ('order_info', 1, 1);

新增 OrderModel

public class OrderModel {    private String id;    private Integer userId;    private Integer itemId;    private BigDecimal itemPrice;    private Integer amount;    private BigDecimal orderPrice;    public String getId() {        return id;    }    public void setId(String id) {        this.id = id;    }    public Integer getUserId() {        return userId;    }    public void setUserId(Integer userId) {        this.userId = userId;    }    public Integer getItemId() {        return itemId;    }    public void setItemId(Integer itemId) {        this.itemId = itemId;    }    public BigDecimal getItemPrice() {        return itemPrice;    }    public void setItemPrice(BigDecimal itemPrice) {        this.itemPrice = itemPrice;    }    public Integer getAmount() {        return amount;    }    public void setAmount(Integer amount) {        this.amount = amount;    }    public BigDecimal getOrderPrice() {        return orderPrice;    }    public void setOrderPrice(BigDecimal orderPrice) {        this.orderPrice = orderPrice;    }}

新增 ItemService

public interface ItemService {    ItemModel createItem(ItemModel itemModel) throws BusinessException;    List
    
      listItem();    ItemModel getItemById(Integer id);    boolean decreaseStock(Integer itemId, Integer amount);    void increaseSales(Integer itemId, Integer amount) throws BusinessException;}
    

新增 ItemServiceImpl

@Servicepublic class ItemServiceImpl implements ItemService {    @Autowired    private ValidatorImpl validator;    @Autowired    private ItemDOMapper itemDOMapper;    @Autowired    private ItemStockDOMapper itemStockDOMapper;    @Override    @Transactional    public ItemModel createItem(ItemModel itemModel) throws BusinessException {        ValidationResult result = validator.validate(itemModel);        if(result.isHasErrors()){            throw new BusinessException(EmBusinessError.PARAMETER_VALIDATION_ERROR, result.getErrMsg());        }        ItemDO itemDO = convertFromModel(itemModel);        itemDOMapper.insertSelective(itemDO);        itemModel.setId(itemDO.getId());        ItemStockDO itemStockDO = convertItemStockFromModel(itemModel);        itemStockDOMapper.insertSelective(itemStockDO);        return getItemById(itemModel.getId());    }    @Override    public List
    
      listItem() {        List
     
       itemDOList = itemDOMapper.listItem();        List
      
        itemModelList = itemDOList.stream().map(itemDO -> {            ItemStockDO itemStockDO = itemStockDOMapper.selectByItemId(itemDO.getId());            ItemModel itemModel = convertFromDataObject(itemDO, itemStockDO);            return itemModel;        }).collect(Collectors.toList());        return itemModelList;    }    @Override    public ItemModel getItemById(Integer id) {        ItemDO itemDO = itemDOMapper.selectByPrimaryKey(id);        if(itemDO == null){            return null;        }        ItemStockDO itemStockDO = itemStockDOMapper.selectByItemId(itemDO.getId());        ItemModel itemModel = convertFromDataObject(itemDO, itemStockDO);        return itemModel;    }    private ItemDO convertFromModel(ItemModel itemModel){        if(itemModel == null){            return null;        }        ItemDO itemDO = new ItemDO();        BeanUtils.copyProperties(itemModel, itemDO);        itemDO.setPrice(itemModel.getPrice().doubleValue());        return itemDO;    }    private ItemStockDO convertItemStockFromModel(ItemModel itemModel){        if(itemModel == null){            return null;        }        ItemStockDO itemStockDO = new ItemStockDO();        itemStockDO.setItemId(itemModel.getId());        itemStockDO.setStock(itemModel.getStock());        return itemStockDO;    }    private ItemModel convertFromDataObject(ItemDO itemDO, ItemStockDO itemStockDO){        if(itemDO == null){            return null;        }        ItemModel itemModel = new ItemModel();        BeanUtils.copyProperties(itemDO, itemModel);        itemModel.setPrice(new BigDecimal(itemDO.getPrice()));        itemModel.setStock(itemStockDO.getStock());        return itemModel;    }    @Override    @Transactional    public boolean decreaseStock(Integer itemId, Integer amount) {        int affectedRow = itemStockDOMapper.decreaseStock(itemId, amount);        return affectedRow > 0;    }    @Override    @Transactional    public void increaseSales(Integer itemId, Integer amount) throws BusinessException {        itemDOMapper.increaseSales(itemId, amount);    }}
      
     
    

新增 OrderController

@Controller("order")@RequestMapping("/order")@CrossOrigin(allowCredentials = "true", allowedHeaders = "*")public class OrderController extends BaseController {    @Autowired    private OrderService orderService;    @Autowired    private HttpServletRequest httpServletRequest;    @RequestMapping(value = "/createorder", method = {RequestMethod.POST}, consumes = {CONTENT_TYPE_FORMED})    @ResponseBody    public CommonReturnType createOrder(@RequestParam(name="itemId") Integer itemId,                                        @RequestParam(name="amount") Integer amount)            throws BusinessException {        Boolean isLogin = (Boolean)httpServletRequest.getSession().getAttribute("LOGIN");        if(isLogin == null || !isLogin.booleanValue()){            throw new BusinessException(EmBusinessError.USER_NOT_LOGIN);        }        UserModel userModel = (UserModel)httpServletRequest.getSession().getAttribute("LOGIN_USER");        OrderModel orderModel = orderService.createOrder(userModel.getId(), itemId, amount);        return CommonReturnType.create(null);    }}

源码：