php中取得URL的根域名的代码

}else if (in_array($last, $this->state_domain)){
$last_2=array_pop($urlarr);
if(in_array($last_1, $this->top_domain)){
$this->domain=$last_2.''.''.$last_1.''.''.$last;
$this->host=implode(''.'', $urlarr);
}else{
$this->host=implode(''.'', $urlarr).$last_2;
$this->domain=$last_1.''.''.$last;
}
}
}
return $this;
}
/**
* 取得域名
* Enter description here ...
*/
public function getDomain(){
return $this->domain;
}
/**
* 取得主机
* Enter description here ...
*/
public function getHost(){
return $this->host;
}
}
?>