接口訪問限流器（頻率限制）

某個接口有訪問頻率限制，限制一分鐘最多能夠訪問XX次，在訪問代碼中增長限流器，以下

    // 限制每分鐘訪問次數
        int tpm = SystemConfigs.getInt(SysConfigKeys.XXX_TPM);
        
        int count = 0, round = 0;
        List<XXX> list = new ArrayList<XXX>();
        
        long startMillis = System.currentTimeMillis();
        while (start.before(end)) {//按時間段不停的訪問接口
            // 預計時間開銷
            long predict = round * 60000 / tpm;
            long duration = System.currentTimeMillis() - startMillis;
            if(predict > duration) {
                // 實際耗時小於預計耗時，sleep
                long waitting = predict - duration;
                try {
                    Thread.sleep(waitting);
                    LOG.debug("XXX同步休眠{}ms. ", waitting);
                } catch (InterruptedException e) {
                    LOG.error("XXX訪問頻率限制失敗：", e);
                }
            }
            round ++;         
            count += this.syncData(start);
            
            start = DateUtils.addDay(start, 1);
        }
     
        LOG.info("總共同步了{}條數據！", count);
        return "XXX同步了" + count + "條數據！";