1.首先设计商品领域模型
public class ItemModel { private Integer id; //商品名称 private String title; //商品价格 private BigDecimal price; //商品的库存 private Integer stock; //商品的描述 private String description; //商品的销量 private Integer sales; //商品描述图片的url private String imgUrl; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public BigDecimal getPrice() { return price; } public void setPrice(BigDecimal price) { this.price = price; } public Integer getStock() { return stock; } public void setStock(Integer stock) { this.stock = stock; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public Integer getSales() { return sales; } public void setSales(Integer sales) { this.sales = sales; } public String getImgUrl() { return imgUrl; } public void setImgUrl(String imgUrl) { this.imgUrl = imgUrl; } }2.设计数据库
两张表：商品表和库存表
3.修改pom文件
<!--允许移动生成的文件--> <verbose>true</verbose> <!--允许自动覆盖文件（生产环境中千万不要这样做）--> <overwrite>false</overwrite>4.修改mybatis-generator配置文件
添加两张表
运行mvn mybatis-generator:generate
5.修改mapper的xml文件
把insert和insertSelective方法后添加属性 keyProperty="id" useGeneratedKeys="true""，使其保持自增
6.创建ItemService接口
public interface ItemService { //创建商品 ItemModel createItem(ItemModel itemModel); //商品列表浏览 List<ItemModel> listItem(); //商品详情浏览 ItemModel getItemById(Integer id); }7.ItemServiceImpl实现类
入参校验
//商品名称 @NotBlank(message = "商品名称不能为空") private String title; //商品价格 @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; //商品的库存 @NotNull(message = "库存不能不填") private Integer stock; //商品的描述 @NotBlank(message = "商品描述信息不能为空") private String description; //商品的销量 @NotBlank(message = "商品图片信息不能为空") private Integer sales; //商品描述图片的url private String imgUrl;实现方法
@Service public 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 { //校验入参 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.convertItemStockDOFromItemModel(itemModel); itemStockDOMapper.insertSelective(itemStockDO); //返回创建完成的对象 return this.getItemById(itemModel.getId()); } private ItemDO convertItemDOFromItemModel(ItemModel itemModel) { if (itemModel == null) { return null; } ItemDO itemDO = new ItemDO(); BeanUtils.copyProperties(itemModel, itemDO); return itemDO; } private ItemStockDO convertItemStockDOFromItemModel(ItemModel itemModel) { if (itemModel == null) { return null; } ItemStockDO itemStockDO = new ItemStockDO(); itemStockDO.setItemId(itemModel.getId()); itemStockDO.setStock(itemModel.getStock()); return itemStockDO; } @Override public List<ItemModel> listItem() { return null; } @Override public ItemModel getItemById(Integer id) { ItemDO itemDO = itemDOMapper.selectByPrimaryKey(id); if (itemDO == null) { return null; } //操作获得库存数量 ItemStockDO itemStockDO = itemStockDOMapper.selectByItemId(itemDO.getId()); //将dataobject-> Model ItemModel itemModel = convertModelFromDataObject(itemDO, itemStockDO); return itemModel; } private ItemModel convertModelFromDataObject(ItemDO itemDO, ItemStockDO itemStockDO) { ItemModel itemModel = new ItemModel(); BeanUtils.copyProperties(itemDO, itemModel); itemModel.setStock(itemStockDO.getStock()); return itemModel; } }8.ItemController
@Controller("/item") @RequestMapping("/item") //跨域请求中，不能做到session共享 @CrossOrigin(origins = {"*"}, allowCredentials = "true") public class ItemController extends BaseController { @Autowired private ItemService itemService; //创建商品的controller @RequestMapping(value = "/create", method = {RequestMethod.POST}, consumes = {CONTENT_TYPE_FORMED}) @ResponseBody public CommonReturnType createItem(@RequestParam(name = "title") String title, @RequestParam(name = "description") String description, @RequestParam(name = "price") BigDecimal price, @RequestParam(name = "stock") Integer stock, @RequestParam(name = "imgUrl") String imgUrl) throws BusinessException { //封装service请求用来创建商品 ItemModel itemModel = new ItemModel(); itemModel.setTitle(title); itemModel.setDescription(description); itemModel.setPrice(price); itemModel.setStock(stock); itemModel.setImgUrl(imgUrl); ItemModel itemModelForReturn = itemService.createItem(itemModel); ItemVO itemVO = convertVOFromModel(itemModelForReturn); return CommonReturnType.create(itemVO); } private ItemVO convertVOFromModel(ItemModel itemModel) { if (itemModel == null) { return null; } ItemVO itemVO = new ItemVO(); BeanUtils.copyProperties(itemModel, itemVO); return itemVO; } }9.商品详情页浏览
@RequestMapping(value = "/get", method = {RequestMethod.GET}) @ResponseBody public CommonReturnType getItem(@RequestParam(name = "id") Integer id) { ItemModel itemModel = itemService.getItemById(id); ItemVO itemVO = convertVOFromModel(itemModel); return CommonReturnType.create(itemVO); }假设我们的需求是按照销量从高到低显示所有商品
1.创建sql语句
在ItemDOMapper.xml中新建方法
<select id="listItem" resultMap="BaseResultMap"> select <include refid="Base_Column_List" /> /*通过销量倒序排序*/ from item ORDER BY sales DESC; </select>2.在ItemDOMapper中创建方法
List<ItemDO> listItem();3.在ItemServiceImpl中实现方法
@Override public List<ItemModel> listItem() { List<ItemDO> itemDOList = itemDOMapper.listItem(); //使用Java8的stream API List<ItemModel> itemModelList = itemDOList.stream().map(itemDO -> { ItemStockDO itemStockDO = itemStockDOMapper.selectByItemId(itemDO.getId()); ItemModel itemModel = this.convertModelFromDataObject(itemDO, itemStockDO); return itemModel; }).collect(Collectors.toList()); return itemModelList; }4.controller层
//商品列表页面浏览 @RequestMapping(value = "/list", method = {RequestMethod.GET}) @ResponseBody public CommonReturnType listItem() { List<ItemModel> itemModelList = itemService.listItem(); List<ItemVO> itemVOList = itemModelList.stream().map(itemModel -> { ItemVO itemVO = this.convertVOFromModel(itemModel); return itemVO; }).collect(Collectors.toList()); return CommonReturnType.create(itemVOList); }