1
public static final String USER_CART_KEY_SUFFIX = "user:cart:";
2
public static final long USER_CART_EXPIRE = 60 * 60 * 24 * 30;

1
private String buildKey(String userId) {
2
    return RedisConst.USER_CART_KEY_SUFFIX + userId;
3
}

1
正式购物车：user:cart:10001
2
临时购物车：user:cart:temp-8f3a...

1
user:cart:{identity}
2
├── field 101 -> CartInfoDTO(skuId=101, skuNum=2, ...)
3
├── field 202 -> CartInfoDTO(skuId=202, skuNum=1, ...)
4
└── field 303 -> CartInfoDTO(skuId=303, skuNum=4, ...)

1
containsKey(skuId)
2
get(skuId)
3
put(skuId, dto)
4
remove(skuId)
5
values()

1
@Data
2
public class CartInfoDTO {
3
    private String userId;
4
    private Long skuId;
5
    private BigDecimal cartPrice;
6
    private Integer skuNum;
7
    private String imgUrl;
8
    private String skuName;
9
    private Integer isChecked = 1;
10
    private BigDecimal skuPrice;
11
    private Date createTime;
12
    private Date updateTime;
13
}

1
cartPrice = 商品当前价格
2
skuPrice  = 商品当前价格

1
@RequestMapping("cart/add/{skuId}/{skuNum}")
2
public Result addCart(@PathVariable Long skuId,
3
                      @PathVariable Integer skuNum,
4
                      HttpServletRequest request) {
5
    String userId = request.getHeader("userId");
6
    if (StringUtils.isBlank(userId)) {
7
        userId = request.getHeader("userTempId");
8
    }
9

10
    cartService.addToCart(skuId, userId, skuNum);
11
    return Result.ok();
12
}

1
@FeignClient("service-product")
2
public interface ProductApiClient {
3
    @GetMapping("/api/product/inner/getSkuInfo/{skuId}")
4
    SkuInfoDTO getSkuInfo(@PathVariable Long skuId);
5

6
    @GetMapping("/api/product/inner/getSkuPrice/{skuId}")
7
    BigDecimal getSkuPrice(@PathVariable Long skuId);
8
}

1
skuNum += 本次数量
2
updateTime = 当前时间
3
isChecked = 1

1
Comparator.comparing(CartInfoDTO::getUpdateTime)
2
        .reversed()

1
public void checkCart(String userId,
2
                      Integer isChecked,
3
                      Long skuId) {
4
    RMap<Long, CartInfoDTO> cart =
5
            redissonClient.getMap(buildKey(userId));
6

7
    CartInfoDTO item = cart.get(skuId);
8
    item.setIsChecked(isChecked);
9
    item.setUpdateTime(new Date());
10
    cart.put(skuId, item);
11
}

1
public void deleteCart(Long skuId, String userId) {
2
    RMap<Long, CartInfoDTO> cart =
3
            redissonClient.getMap(buildKey(userId));
4
    cart.remove(skuId);
5
}

1
public void deleteChecked(String userId) {
2
    RMap<Long, CartInfoDTO> cart =
3
            redissonClient.getMap(buildKey(userId));
4

5
    Iterator<Map.Entry<Long, CartInfoDTO>> iterator =
6
            cart.entrySet().iterator();
7

8
    while (iterator.hasNext()) {
9
        Map.Entry<Long, CartInfoDTO> entry = iterator.next();
10
        if (entry.getValue().getIsChecked() == 1) {
11
            iterator.remove();
12
        }
13
    }
14
}

1
初始数量 1
2
A 读取 1
3
B 读取 1
4
A 写入 2
5
B 写入 2
6
最终 2，而非 3