1、統計當前登入使用者數
2、統計近五分鐘的線上裝置數量

@Autowired
private StringRedisTemplate stringRedisTemplate;

    /**
     * 設定bitmaps，統計線上裝置數
     *
     * @param deviceId
     */
    private void setBitmaps(String key, Long deviceId) {
        try {
            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm");
            //獲取當前時間
            String curDate = formatter.format(new Date(System.currentTimeMillis()));
            redisTemplate.opsForValue().setBit(key + curDate, deviceId, true);
        } catch (Exception e) {
            log.error("setBitmaps,deviceId is {}, exception is {}", deviceId, e);
        }
    }

    /**
     * 統計近五分鐘線上數
     */
    public void getOnlineCount() {
        try {
            String key = "aiot:towercrane:device:online:";
            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm");
            //獲取當前時間
            String curDate = key + formatter.format(new Date(System.currentTimeMillis()));
            String curDateBeforeOne = key + formatter.format(new Date(System.currentTimeMillis() - 1 * 60 * 1000L));
            String curDateBeforeTwo = key + formatter.format(new Date(System.currentTimeMillis() - 2 * 60 * 1000L));
            String curDateBeforeThree = key + formatter.format(new Date(System.currentTimeMillis() - 3 * 60 * 1000L));
            String curDateBeforeFour = key + formatter.format(new Date(System.currentTimeMillis() - 4 * 60 * 1000L));
            long count = (long) stringRedisTemplate.execute((RedisCallback<Long>) con -> con.bitOp(RedisStringCommands.BitOperation.AND, curDate.getBytes(), curDateBeforeOne.getBytes(), curDateBeforeTwo.getBytes(), curDateBeforeThree.getBytes(), curDateBeforeFour.getBytes()));
            System.out.println(count);
        } catch (Exception e) {
            log.error("getAttendanceOnlineCount exception is {}", e);
        }
    }