按集合中的某个的字段拆分成若干个集合

前言

不同商家的商品，购物车统一结算按卖家拆单

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将一个list集合，按集合中的某个的字段拆分成若干个集合

List<ShopProductVo> shopProductVos = new ArrayList<>();
        for (ShopCart shopCart : shopCarts) {
     
        	//查找出购物车商品，放入集合
            shopProductVos.add(shopStockSizeMapper.selectProductVoByS_id(shopCart.getsId()));
        }
        //将集合按卖家分单
        List<List<ShopProductVo>> groupList = new ArrayList<>();
        //java8:Collectors.groupingBy根据一个或多个属性对集合中的项目进行分组
        shopProductVos.stream().collect(Collectors.groupingBy(ShopProductVo::getAccount_id, Collectors.toList()))
                .forEach((accountId, shopProductVoList) -> {
     
                    groupList.add(shopProductVoList);
                });