@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Autowired
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result likeBlog(Long id) {
        // 獲取登錄用戶
        Long userId = UserHolder.getUser().getId();
        // 判斷當(dāng)前登錄用戶是否已經(jīng)點(diǎn)贊
        String key = "blog:like:" + id;
        Boolean isMember = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
        if(BooleanUtil.isFalse(isMember)){
            // 未點(diǎn)贊
            // 數(shù)據(jù)庫點(diǎn)贊數(shù)+1
            boolean isSuccess = update().setSql("like = like + 1").eq("id",id).update();
            // 保存用戶到Redis集合中
            if(isSuccess){
                stringRedisTemplate.opsForSet().add(key, userId.toString());
            }
        } else {
            // 已點(diǎn)贊，取消點(diǎn)贊
            // 數(shù)據(jù)庫點(diǎn)贊數(shù)-1
            boolean isSuccess = update().setSql("like = like - 1").eq("id",id).update();
            // 移除set集合中的用戶
            stringRedisTemplate.opsForSet().remove(key, userId.toString());
        }
        return Result.ok();
    }
}

@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Autowired
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result likeBlog(Long id) {
        // 獲取登錄用戶
        Long userId = UserHolder.getUser().getId();
        // 判斷當(dāng)前登錄用戶是否已經(jīng)點(diǎn)贊
        String key = "blog:like:" + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score == null){
            // 未點(diǎn)贊
            // 數(shù)據(jù)庫點(diǎn)贊數(shù)+1
            boolean isSuccess = update().setSql("like = like + 1").eq("id",id).update();
            // 保存用戶到Redis集合中
            if(isSuccess){
                stringRedisTemplate.opsForZSet().add(key, userId.toString(), System.currentTimeMillis());
            }
        } else {
            // 已點(diǎn)贊，取消點(diǎn)贊
            // 數(shù)據(jù)庫點(diǎn)贊數(shù)-1
            boolean isSuccess = update().setSql("like = like - 1").eq("id",id).update();
            // 移除set集合中的用戶
            stringRedisTemplate.opsForZSet().remove(key, userId.toString());
        }
        return Result.ok();
    }
}

@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Autowired
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryBlogLikes(Long id) {
        String key = "blog:like:" + id;
        // 查詢top5的點(diǎn)贊用戶 zrange key 0 4
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5 == null || top5.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        // 解析出集合中的用戶的id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        // 根據(jù)id查詢用戶,并將類型由User轉(zhuǎn)為UserDTO,隨后轉(zhuǎn)換為List集合
        String idStr = StrUtil.join(",",ids);
//        List<UserDTO> userDTOs = userService.listByIds(ids).stream()
//                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
//                .collect(Collectors.toList());
        List<UserDTO> userDTOs = userService.query()
                .in("id",ids).last("order by field(id," + idStr +")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOs);
    }
}

userService.query().in("id", ids).last("order by field(id," + idStr + ")")