`// 遍历订单商品
for (OrderItemVO newBeeMallOrderItem : listMap.getOrDefault(orderId, Collections.emptyList())) {
Long goodsId = newBeeMallOrderItem.getGoodsId();
Long categoryId = newBeeMallOrderItem.getCategoryId();
RelateDTO relateDTO = new RelateDTO();
relateDTO.setUserId(newBeeMallOrder.getUserId());
relateDTO.setProductId(goodsId);
relateDTO.setCategoryId(categoryId);
// 通过计算商品购买次数,来建立相似度
List list = goodsListMap.getOrDefault(goodsId, Collections.emptyList());
int sum = list.stream().mapToInt(OrderItemVO::getGoodsCount).sum();
relateDTO.setIndex(sum);
relateDTOList.add(relateDTO);