public static function getPushMessage($pushEndTime = 0)
{
if ($pushEndTime == 0) {
$pushEndTime = time();
}
$stn = DB::getInstance()->prepare("SELECT * FROM message WHERE pushEndTime>?");
$stn->bindValue(1, $pushEndTime, DB::PARAM_INT);
$stn->execute();
return $stn->fetchAll(DB::FETCH_CLASS, __CLASS__);
}