SpringBoot构建电商基础秒杀项目-----学习笔记4

商品模型

在视频的一开始，视频说应该先设计领域模型。（我一般都是先设计数据库的，这里涨知识了）

在这里，库存用了另外一张表。

ItemModel.java

@Data
public class ItemModel {

    private Integer id;

    @NotBlank(message = "商品名称不能为空")
    private String title;

    @NotNull(message = "商品价格不能为空")
    @Min(value = 0, message = "商品价格必须大于0")
    private BigDecimal price;

    @NotNull(message = "库存不能为空")
    @Min(value = 0, message = "库存必须大于0")
    private Integer stock;

    @NotNull(message = "商品表述信息不能为空")
    private String description;

    //销量
    private Integer sales;

    @NotNull(message = "商品图片不能为空")
    private String imgUrl;
}

由于需要重新利用mybatis的generator，所以要被自动覆盖设置为false。避免之前的改动没了（在这里，我之前看的视频时，自己写的mapper.xml最好用一个新的文件保存）

 

mybatis-generator.xml增加下列代码。同时最好注释之前生成的类的代码

重新运行mybatis-generator。生成类【如果用idea可以直接利用maven插件，点击即可】

对所有的增加语句添加获取自增id

keyProperty="id" useGeneratedKeys="true"    

给 ItemStockDOMapper 添加方法

ItemStockDO selectByItemId(Integer itemId);

ItemStockDOMapper.xml增加下列句子

    select
    
    from item_stock
    where item_id = #{itemId,jdbcType=INTEGER}
  

创建 ItemService

public interface ItemService {
    //创建商品
    ItemModel createItem(ItemModel itemModel) throws BusinessException;

    //商品列表浏览
    List listItems();

    //商品详情 根据Id查找。
    ItemModel getItemById(Integer id);
}

创建 ItemServiceImpl

@Service
public class ItemServiceImpl implements ItemService {

    @Autowired
    private ValidatorImpl validator;

    @Autowired
    private ItemDOMapper itemDOMapper;

    @Autowired
    private ItemStockDOMapper itemStockDOMapper;

    @Transactional
    @Override
    public ItemModel createItem(ItemModel itemModel) throws BusinessException {
        //检验入参
        ValidationResult result = validator.validate(itemModel);
        if (result.isHasErrors()) {
            throw new BusinessException(EmBusinessError.PARAMETER_VALIDATION_ERROR, result.getErrMsg());
        }
        //转化itemModel -> dataObject
        ItemDO itemDO = this.convertItemDOFromItemModel(itemModel);
        //写入数据库
        itemDOMapper.insertSelective(itemDO);
        itemModel.setId(itemDO.getId());
        ItemStockDO itemStockDO = this.covertItemStockDOFromItemModel(itemModel);
        itemStockDOMapper.insertSelective(itemStockDO);
        //返回创建完成的对象
        return this.getItemById(itemModel.getId());
    }

    @Override
    public List listItems() {
        return null;
    }

    @Override
    public ItemModel getItemById(Integer id) {
        ItemDO itemDO = itemDOMapper.selectByPrimaryKey(id);
        if (itemDO == null)
            return null;
        //获取库存
        ItemStockDO itemStockDO = itemStockDOMapper.selectByItemId(itemDO.getId());
        ItemModel itemModel = convertModelFromDataObject(itemDO, itemStockDO);
        return itemModel;
    }

    private ItemDO convertItemDOFromItemModel(ItemModel itemModel) {
        if (itemModel == null)
            return null;
        ItemDO itemDO = new ItemDO();
        BeanUtils.copyProperties(itemModel, itemDO);
        //因为一个是double类型。 一个是bigDecimal类型。
        //所以这里需要手动转换
        itemDO.setPrice(itemModel.getPrice().doubleValue());
        return itemDO;
    }

    private ItemStockDO covertItemStockDOFromItemModel(ItemModel itemModel) {
        if (itemModel == null)
            return null;
        ItemStockDO itemStockDO = new ItemStockDO();
        itemStockDO.setItemId(itemModel.getId());
        itemStockDO.setStock(itemModel.getStock());
        return itemStockDO;
    }

    private ItemModel convertModelFromDataObject(ItemDO itemDO, ItemStockDO itemStockDO) {
        ItemModel itemModel = new ItemModel();
        BeanUtils.copyProperties(itemDO, itemModel);
        itemModel.setPrice(new BigDecimal(itemDO.getPrice()));
        itemModel.setStock(itemStockDO.getStock());
        return itemModel;
    }
}

创建ItemVO

@Data
public class ItemVO {
    private Integer id;

    private String title;

    private BigDecimal price;

    //库存
    private Integer stock;

    private String description;

    //销量
    private Integer sales;

    private String imgUrl;
}

创建 ItemController

@Controller("item")
@RequestMapping("/item")
@CrossOrigin(allowCredentials = "true", allowedHeaders = "*")
public class ItemController extends BaseController {

    @Autowired
    private ItemService itemService;

    @RequestMapping(value = "/create", method = {RequestMethod.POST}, consumes = {CONTENT_TYPE_FORMED})
    @ResponseBody
    public CommonReturnType createItem(ItemModel item) throws BusinessException {

        ItemModel itemModel = itemService.createItem(item);
        ItemVO itemVO = convertFromModel(itemModel);
        return CommonReturnType.create(itemVO);
    }

    @RequestMapping(value = "/get", method = {RequestMethod.GET})
    @ResponseBody
    public CommonReturnType getItem(@RequestParam(name="id") Integer id){
        ItemModel itemModel = itemService.getItemById(id);
        ItemVO itemVO = convertFromModel(itemModel);
        return CommonReturnType.create(itemVO);
    }

    private ItemVO convertFromModel(ItemModel itemModel){
        if(itemModel == null){
            return null;
        }
        ItemVO itemVO = new ItemVO();
        BeanUtils.copyProperties(itemModel, itemVO);
        return itemVO;
    }

页面绘制【来自于https://www.cnblogs.com/victorbu/p/10573393.html】

    
        
        
    
    
    
        

            
                
                    
创建商品
                    
                        
                            
                        
                        
                            
                        
                        
                            
                        
                        
                            
                        
                        
                            
                        
                        
                        
                            提交
                        
                    
                
            
        
    
    
    
    
    
    

商品详情

ItemDOMapjie'接口增加新方法

List listItem();

添加对应的xml代码（ItemDOMapper.xml）。

 
    select
    
    from item
    order by sales desc ;
  

ItemServiceImpl 编写对应方法

 @Override
    public List listItems() {
        List itemDOS = itemDOMapper.listItem();
        List itemModels = new ArrayList<>();
        for(int i = 0;i < itemDOS.size(); i++){
            ItemStockDO itemStockDO = itemStockDOMapper.selectByItemId(itemDOS.get(i).getId());
            itemModels.add(convertModelFromDataObject(itemDOS.get(i),itemStockDO));
        }
        return itemModels;


        // java 8的Stream方法
//        List itemModelList = itemDOS.stream().map(itemDO -> {
//            ItemStockDO itemStockDO = itemStockDOMapper.selectByItemId(itemDO.getId());
//            ItemModel itemModel = convertModelFromDataObject(itemDO,itemStockDO);
//            return itemModel;
//        }).collect(Collectors.toList());
//        return itemModelList;
    }

ItemController编写对应代码

 @RequestMapping(value = "/list", method = RequestMethod.GET)
    @ResponseBody
    public CommonReturnType listItem(){
        List itemModels = itemService.listItems();
        List itemVOs = itemModels.stream().map(itemModel -> {
            ItemVO itemVO = convertFromModel(itemModel);
            return itemVO;
        }).collect(Collectors.toList());
        return CommonReturnType.create(itemVOs);
    }

页面代码。【由于参考的代码的页面没有写好，自己改了点东西。  不过图片没有显示出来。。。】

总结

商品信息的模块就做完了。 感觉也差不多吧，只是简单的CRUD。不过有好多的转化函数需要些，比如dataObject转换成model型的。 可能是之前做的小设计没有出现过这么多东西吧，感觉总是忘记。