public static boolean isMobFileExpired(ColumnFamilyDescriptor column, long current,
    String fileDate) {
    if (column.getMinVersions() > 0) {
      return false;
    }
    long timeToLive = column.getTimeToLive();
    if (Integer.MAX_VALUE == timeToLive) {
      return false;
    }

    Date expireDate = new Date(current - timeToLive * 1000);
    expireDate = new Date(expireDate.getYear(), expireDate.getMonth(), expireDate.getDate());
    try {
      Date date = parseDate(fileDate);
      if (date.getTime() < expireDate.getTime()) {
        return true;
      }
    } catch (ParseException e) {
      LOG.warn("Failed to parse the date " + fileDate, e);
      return false;
    }
    return false;
  }
Checks if the mob file is expired.
@param column   The descriptor of the current column family.
@param current  The current time.
@param fileDate The date string parsed from the mob file name.
@return True if the mob file is expired.
hbase-server/src/main/java/org/apache/hadoop/hbase/mob/MobUtils.java