shop--10.商品--商品编辑（后端）--Controller层

主要逻辑：

• 根据前端url中productId ,调用service层的接口获取product信息，以便前端能在商品编辑页面展示对应的数据
• 修改商品

/**
     * 通过商品id获取商品信息
     * 
     * @param productId
     * @return
     */
    @RequestMapping(value="/getproductbyid",method = RequestMethod.GET)
    @ResponseBody
    private Map<String, Object> getProductById(@RequestParam Long productId){
        Map<String, Object> modelMap = new HashMap<String, Object>();
        //非空判断
        if(productId > -1) {
            //获取商品信息
            Product product = productService.getProductById(productId);
            //获取该店铺下的商品类别列表
            List<ProductCategory> productCategoryList = productCategoryService.getProductCategoryList(product.getShop().getShopId());
            modelMap.put("product", product);
            modelMap.put("productCategoryList", productCategoryList);
            modelMap.put("success", true);
        }else {
            modelMap.put("success", false);
            modelMap.put("errMsg", "empty productId");
        }
        return modelMap;
    }
    
    @RequestMapping(value="/modifyproduct",method=RequestMethod.POST)
    private Map<String, Object> modifyProduct(HttpServletRequest request){
        Map<String, Object> modelMap = new HashMap<String,Object>();
        //是商品编辑时候调用还是上下架操作的时候调用
        //若为前者则进行验证码判断，后者则跳过验证码判断
        boolean statusChange = HttpServletRequestUtil.getBoolean(request, "statusChange");
        ////步骤1：验证码校验
        if(!statusChange&&!CodeUtil.checkVerifyCode(request)) {
            modelMap.put("success", false);
            modelMap.put("errMsg", "输入了错误的验证码");
            return modelMap;
        }
        //接受前端参数的初始化，包括商品，缩略图，详情图列表实体类
        ObjectMapper objectMapper = new ObjectMapper();
        Product product = null;
        ImageHolder thumbnail = null;
        List<ImageHolder> productImgList = new ArrayList<ImageHolder>();
        CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver(request.getSession().getServletContext());
        //步骤2：使用FastJson提供的api,实例化Product 构造调用service层的第一个参数
        //接受前端参数变量的初始化，商品，缩略图，详情图列表实体类
        String productStr = HttpServletRequestUtil.getString(request, "productStr");
        try {
            product = objectMapper.readValue(productStr, Product.class);
        } catch (Exception e) {
            modelMap.put("success", false);
            modelMap.put("errMsg", e.toString());
            return modelMap;
        }
        //若请求中存在文件流，则取出相关的文件（包括缩略图和详情图）
        try {
            if(commonsMultipartResolver.isMultipart(request)) {
                MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest) request;
                //取出缩略图并构建ImageHolder对象
                CommonsMultipartFile thumbnailFile = (CommonsMultipartFile) multipartHttpServletRequest.getFile("thumbnail");
                if(thumbnailFile!=null) {
                    thumbnail = new ImageHolder(thumbnailFile.getOriginalFilename(), thumbnailFile.getInputStream());
                }
                //取出详情图并构建List<ImageHolder>列表对象，最多支持六张图片上传
                for(int i = 0;i<IMAGEMAXCOUNT;i++) {
                    CommonsMultipartFile productImgFile = (CommonsMultipartFile) multipartHttpServletRequest.getFile("productImg" + i);
                    if(productImgFile != null) {
                        //若取出的第i个详情图片文件流不为空，则将其加入详情图列表
                        ImageHolder productImg = new ImageHolder(productImgFile.getOriginalFilename(), productImgFile.getInputStream());
                        productImgList.add(productImg);
                    }else {
                        //若取出的第i个详情图片文件流为空，则终止循环
                        break;
                    }
                }
            }
        }catch (Exception e) {
            modelMap.put("success", false);
            modelMap.put("errMsg", e.toString());
            return modelMap;
        }
        // Step4 调用Service层
        if(product != null && thumbnail != null && productImgList.size() > 0) {
            try {
                //从session中获取shop信息，不依赖前端的传递更安全
                Shop currentShop = (Shop) request.getSession().getAttribute("currentShop");
                product.setShop(currentShop);
                //调用modifyProduct
                ProductExecution pe = productService.modifyProduct(product, thumbnail, productImgList);
                if(pe.getState() == ProductStateEnum.SUCCESS.getState()) {
                    modelMap.put("success", true);
                }else {
                    modelMap.put("success", false);
                    modelMap.put("errMsg", pe.getStateInfo());
                }
            }catch (ProductOperationException e) {
                modelMap.put("success", false);
                modelMap.put("errMsg", e.toString());
                return modelMap;
            }
        }else {
            modelMap.put("success", false);
            modelMap.put("errMsg", "请输入商品信息");
        }
        return modelMap;
    }