#vulnerable code 
                                @PostMapping("/update")
    public Object update(@LoginAdmin Integer adminId, @RequestBody GoodsAllinone goodsAllinone) {
        if (adminId == null) {
            return ResponseUtil.unlogin();
        }

        LitemallGoods goods = goodsAllinone.getGoods();
        LitemallGoodsAttribute[] attributes = goodsAllinone.getAttributes();
        LitemallGoodsSpecification[] specifications = goodsAllinone.getSpecifications();
        LitemallProduct[] products = goodsAllinone.getProducts();

        // 开启事务管理
        DefaultTransactionDefinition def = new DefaultTransactionDefinition();
        def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
        TransactionStatus status = txManager.getTransaction(def);
        try {

            // 商品基本信息表litemall_goods
            goodsService.updateById(goods);

            Integer gid = goods.getId();
            specificationService.deleteByGid(gid);
            attributeService.deleteByGid(gid);
            productService.deleteByGid(gid);

            // 商品规格表litemall_goods_specification
            Map<String, Integer> specIds = new HashMap<>();
            for (LitemallGoodsSpecification specification : specifications) {
                specification.setGoodsId(goods.getId());
                specification.setAddTime(LocalDateTime.now());
                specificationService.add(specification);
                specIds.put(specification.getValue(), specification.getId());
            }

            // 商品参数表litemall_goods_attribute
            for (LitemallGoodsAttribute attribute : attributes) {
                attribute.setGoodsId(goods.getId());
                attribute.setAddTime(LocalDateTime.now());
                attributeService.add(attribute);
            }

            // 商品货品表litemall_product
            for (LitemallProduct product : products) {
                product.setGoodsId(goods.getId());
                product.setAddTime(LocalDateTime.now());
                productService.add(product);
            }
        } catch (Exception ex) {
            txManager.rollback(status);
            logger.error("系统内部错误", ex);
        }
        txManager.commit(status);

        qCodeService.createGoodShareImage(goods.getId().toString(), goods.getPicUrl(), goods.getName());

        return ResponseUtil.ok();
    } 
                            #location 54 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @PostMapping("/update")
    public Object update(@LoginAdmin Integer adminId, @RequestBody GoodsAllinone goodsAllinone) {
        if (adminId == null) {
            return ResponseUtil.unlogin();
        }

        LitemallGoods goods = goodsAllinone.getGoods();
        LitemallGoodsAttribute[] attributes = goodsAllinone.getAttributes();
        LitemallGoodsSpecification[] specifications = goodsAllinone.getSpecifications();
        LitemallProduct[] products = goodsAllinone.getProducts();

        // 开启事务管理
        DefaultTransactionDefinition def = new DefaultTransactionDefinition();
        def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
        TransactionStatus status = txManager.getTransaction(def);
        try {

            //将生成的分享图片地址写入数据库
            qCodeService.createGoodShareImage(goods.getId().toString(), goods.getPicUrl(), goods.getName());
            goods.setShareUrl(qCodeService.getShareImageUrl(goods.getId().toString()));

            // 商品基本信息表litemall_goods
            goodsService.updateById(goods);

            Integer gid = goods.getId();
            specificationService.deleteByGid(gid);
            attributeService.deleteByGid(gid);
            productService.deleteByGid(gid);

            // 商品规格表litemall_goods_specification
            Map<String, Integer> specIds = new HashMap<>();
            for (LitemallGoodsSpecification specification : specifications) {
                specification.setGoodsId(goods.getId());
                specification.setAddTime(LocalDateTime.now());
                specificationService.add(specification);
                specIds.put(specification.getValue(), specification.getId());
            }

            // 商品参数表litemall_goods_attribute
            for (LitemallGoodsAttribute attribute : attributes) {
                attribute.setGoodsId(goods.getId());
                attribute.setAddTime(LocalDateTime.now());
                attributeService.add(attribute);
            }

            // 商品货品表litemall_product
            for (LitemallProduct product : products) {
                product.setGoodsId(goods.getId());
                product.setAddTime(LocalDateTime.now());
                productService.add(product);
            }
        } catch (Exception ex) {
            txManager.rollback(status);
            logger.error("系统内部错误", ex);
        }
        txManager.commit(status);

        qCodeService.createGoodShareImage(goods.getId().toString(), goods.getPicUrl(), goods.getName());

        return ResponseUtil.ok();
    }