php中取得URL的根域名的代码

<?php
/**
* 取得根域名
*
* @author lonely
* @create 2011-3-11
* @version 0.1
* @lastupdate lonely
* @package Sl
*/
class Sl_RootDomain{
private static $self;
private $domain=null;
private $host=null;
private $state_domain;
private $top_domain;
/**
* 取得域名分析实例
* Enter description here ...
*/
public static function instace(){
if(!self::$self)
self::$self=new self();
return self::$self;
}
private function __construct(){
$this->state_domain=array(
al,dz,af,ar,ae,aw,om,az,eg,et,ie,ee,ad,ao,ai,ag,at,au,mo,bb,pg,bs,pk,py,ps,bh,pa,br,by,bm,bg,mp,bj,be,is,pr,ba,pl,bo,bz,bw,bt,bf,bi,bv,kp,gq,dk,de,tl,tp,tg,dm,do,ru,ec,er,fr,fo,pf,gf,tf,va,ph,fj,fi,cv,fk,gm,cg,cd,co,cr,gg,gd,gl,ge,cu,gp,gu,gy,kz,ht,kr,nl,an,hm,hn,ki,dj,kg,gn,gw,ca,gh,ga,kh,cz,zw,cm,qa,ky,km,ci,kw,cc,hr,ke,ck,lv,ls,la,lb,lt,lr,ly,li,re,lu,rw,ro,mg,im,mv,mt,mw,my,ml,mk,mh,mq,yt,mu,mr,us,um,as,vi,mn,ms,bd,pe,fm,mm,md,ma,mc,mz,mx,nr,np,ni,ne,ng,nu,no,nf,na,za,aq,gs,eu,pw,pn,pt,jp,se,ch,sv,ws,yu,sl,sn,cy,sc,sa,cx,st,sh,kn,lc,sm,pm,vc,lk,sk,si,sj,sz,sd,sr,sb,so,tj,tw,th,tz,to,tc,tt,tn,tv,tr,tm,tk,wf,vu,gt,ve,bn,ug,ua,uy,uz,es,eh,gr,hk,sg,nc,nz,hu,sy,jm,am,ac,ye,iq,ir,il,it,in,id,uk,vg,io,jo,vn,zm,je,td,gi,cl,cf,cn,yr
);
$this->top_domain=array(com,arpa,edu,gov,int,mil,net,org,biz,info,pro,name,museum,coop,aero,xxx,idv,me,mobi);
$this->url=$_SERVER[HTTP_HOST];
}
/**
* 设置URL
* Enter description here ...
* @param string $url
*/
public function setUrl($url=null){
$url=$url?$url:$this->url;
if(empty($url))return $this;
if(!preg_match("/^http::/is", $url))
$url="http://".$url;
$url=parse_url(strtolower($url));
$urlarr=explode(".", $url[host]);
$count=count($urlarr);
if ($count<=2){
$this->domain=array_pop($url);
}else if ($count>2){
$last=array_pop($urlarr);
$last_1=array_pop($urlarr);
if(in_array($last, $this->top_domain)){
$this->domain=$last_1...$last;
$this->host=implode(., $urlarr);
}else if (in_array($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;
}
}
?>