java8 新特性

最新推荐文章于 2024-05-21 11:11:26 发布

银月游侠

最新推荐文章于 2024-05-21 11:11:26 发布

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本文链接：https://blog.youkuaiyun.com/u011731145/article/details/88716076

LIst 过滤转map

        List<ShopeeItem> existShopeeItems = records.stream().map(a -> {
            String itemId = a.getItemId();
            String itemSku = a.getItemSku();
            ShopeeItem existShopeeItem = customShopeeItemMapper.selectByItemIdAndSku(itemId, itemSku);
            return existShopeeItem;

        }).filter(a -> a != null).collect(Collectors.toList());

        // 封装map
        Map<String, ShopeeItem> existMap = existShopeeItems.stream().collect(Collectors.toMap(item -> {
            return item.getItemId() + "_" + item.getItemSku();
        }, item -> {
            return item;
        }));

        // 结合一起
        Map<String, ShopeeItem> existMap = records.stream().map(a -> {
            String itemId = a.getItemId();
            String itemSku = a.getItemSku();
            ShopeeItem existShopeeItem = customShopeeItemMapper.selectByItemIdAndSku(itemId, itemSku);
            return existShopeeItem;

        }).filter(a -> a != null).collect(Collectors.toMap(item -> {
            return item.getItemId() + "_" + item.getItemSku();
        }, item -> {
            return item;
        }));