Ajax跨域代理访问网络资源的实现代码

<script language="jscript" runat="server">
/*
在VBS里面的调用方法
dim myhttp
set myhttp = SmartHttp(url,method,data); //三个参数均可选
属性：
url：String，请求的URL地址
method：String，请求的方法
data：String，请求的数据
charset：String，请求的URL返回数据的编码
status：Int，请求返回的状态码
readyState：Int，同HTTP请求的当前通讯状态，1、2、3、4
dataset：Object，请求的数据，如果增加了，会将这部分数据附加到data属性
dataset属性：
charset：String，发送数据的编码
dataset方法：
append(key,value,noencode)：添加数据
remove(key)：移除某个数据项
isexists(key)：判断某个数据项是不是存在
clear：清除所有数据项
方法：
header(headstr)：设置请求头，项和值之间用:分开
timeout(t1,t2,t3,t4)：设置超时时间
send()：发送请求
getbinary：获取服务器返回的二进制数据
gettext(charset)：获取指定编码的文本
getjson(charset)：获取指定编码的json数据
getheader(key)：获取服务器返回的响应头
getxml(charset)：获取指定编码的xml数据
*/
function SmartHttp(url,method,data){
return new _SmartHttp(url,method,data);
}

function _SmartHttp(url,method,data){
if(typeof method=="undefined") method="GET";
if(typeof data=="undefined") data="";
method = method.toUpperCase();
method = method!="POST" ? "GET" : "POST";
this.timeout=[10000,10000,10000,10000];
this.method = method;
this.url=url;
this.data=data;
this.charset="gb2312";
this.http=null;
this.headers=[];
this.status=0;
this.readyState=0;
this.content=null;
this.msg="";
this.dataset={
charset:"gb2312",
data:[],
append:function(key,value,noencode){
var fn=null;
if(this.charset.toLowerCase()=="utf-8"){fn = encodeURIComponent;}else{fn = escape;}
if(noencode==true){fn=function(_str){return _str;}}
this.data.push({"key":fn(key),"value":fn(value)});
},
remove:function(key){
if(this.data.length<=0) return false;
var _data=[];
for(var i=0;i<this.data.length;i++){
if(this.data[i].key!=key){
_data.push(this.data[i]);
}
}
this.data = _data;
},
isexists:function(key){
if(this.data.length<=0) return false;
for(var i=0;i<this.data.length;i++){
if(this.data[i].key==key){
return true;
}
}
return false;
},
clear:function(){
this.dataset.data=[];
}
};
}

_SmartHttp.prototype.init=function(){
var datasetstr="";
if(this.dataset.data.length>0){
for(var i=0;i<this.dataset.data.length;i++){
datasetstr += this.dataset.data[i].key + "=" + this.dataset.data[i].value + "&";
}
}
if(datasetstr!="") datasetstr = datasetstr.substr(0,datasetstr.length-1);
if(this.data==""){this.data = datasetstr;}else{if(datasetstr!="")this.data+= "&" + datasetstr;}
if(this.data=="")this.data=null;
//this.url += ((this.url.indexOf("?")<0) ? "?" : "&") + "jornd=" + this.getrnd();
if(this.method=="GET" && this.data!=null) this.url += "&" + this.data;
if(this.method=="POST") this.headers.push("Content-Type:application/x-www-form-urlencoded");
if(!this.charset || this.charset=="") this.charset = "gb2312";
};

_SmartHttp.prototype.header=function(headstr){
if(headstr.indexOf(":")>=0) this.headers.push(headstr);
return this;
};

_SmartHttp.prototype.timeout=function(){
if(arguments.length>4){return this;}
for(var i =0;i<arguments.length;i++){
if(!isNaN(arguments[i])){
this.timeout[i] = parseInt(arguments[i]);
}
}
return this;
};

_SmartHttp.prototype.send=function(){
this.init();
var _http = this.getobj();
if(_http==null){return this;}
try{
_http.setTimeouts(this.timeout[0], this.timeout[1], this.timeout[2], this.timeout[3]);
}catch(ex){}
_http.open(this.method,this.url,false);
if(this.headers.length>0){
for(var i=0;i<this.headers.length;i++){
var Sindex = this.headers[i].indexOf(":");
var key = this.headers[i].substr(0,Sindex);
var value = this.headers[i].substr(Sindex+1);
_http.setRequestHeader(key,value);
}
}
_http.send(this.data);
this.readyState = _http.readyState;
if(_http.readyState==4){
this.status = parseInt(_http.status);
this.http = _http;
this.content = _http.responseBody;
}
return this;
}

_SmartHttp.prototype.getbinary=function(){
return this.content;
};

_SmartHttp.prototype.gettext=function(charset){
try{
return this.b2s(this.content,charset ? charset : this.charset);
}catch(ex){
this.msg = ex.description;
return "";
}
};

_SmartHttp.prototype.getjson=function(charset){
try{
var _json=null;
eval("_json=(" + this.gettext(charset) + ");");
return _json;
}catch(ex){
this.msg = ex.description;
return null;
}
};

_SmartHttp.prototype.getheader=function(key){
if(key){
if(key.toUpperCase()=="SET-COOKIE"){
key = key.replace("-","\-");
var headers = this.http.getAllResponseHeaders();
var regexp = new RegExp("\n" + key + "\:(.+?)\r","ig");
var resstr = "";
while((res = regexp.exec(headers))!=null){
var val = res[1].trim();
resstr = resstr + val.substr(0,val.indexOf(";")) + "; "
}
if(resstr!=""){
resstr = resstr.substr(0,resstr.lastIndexOf(";"));
}
return resstr;
}else{
return this.http.getResponseHeader(key);
}
}else{return this.http.getAllResponseHeaders();}
};

_SmartHttp.prototype.getxml=function(charset){
try{
var _dom = new ActiveXObject("MSXML2.DOMDocument");
_dom.loadXML(this.gettext(charset));
return _dom;
}catch(ex){
this.msg = ex.description;
return null;
}
};
_SmartHttp.prototype.getobj = function (){
var b=null;
var httplist = ["MSXML2.serverXMLHttp.3.0","MSXML2.serverXMLHttp","MSXML2.XMLHttp.3.0","MSXML2.XMLHttp","Microsoft.XMLHttp"];
for(var i = 0;i<=httplist.length -1;i++){
try{
b= new ActiveXObject(httplist[i]);
(function(o){
_SmartHttp.prototype.getobj = function(){return new ActiveXObject(o)};
})(httplist[i]);
return b;
}catch(ex){
eval("this.msg = ex.description;");
}
}
return b;
};

_SmartHttp.prototype.getrnd = function (){return Math.random().toString().substr(2);};

_SmartHttp.prototype.b2s = function(bytSource, Cset){ //ef bb bf,c0 fd
var Objstream,c1,c2,c3;
var byts;
Objstream =Server.CreateObject("ADODB.Stream");
Objstream.Type = 1;
Objstream.Mode = 3;
Objstream.Open();
Objstream.Write(bytSource);
Objstream.Position = 0;
Objstream.Type = 2;
Objstream.CharSet = Cset;
byts = Objstream.ReadText();
Objstream.Close();
Objstream = null;
return byts;
};
_SmartHttp.prototype.urlencode=function(str){ return encodeURIComponent(str);};
_SmartHttp.prototype.urldecode=function(str){ return decodeURIComponent(str);};
String.prototype.trim = function(){return this.replace(/(^(\s+)|(\s+)$)/igm,"");};
</script>

<!--#include file="smart.asp"-->
<%
Response.charset="utf-8"
dim url,method,data,charset
url =Request.Form("targeturl")
method =Request.Form("method")
data =Request.Form("data")
charset = Request.Form("charset")
if charset = "" then charset = "GB2312"
response.Write SmartHttp(url,method,data).send().gettext(charset)
set myhttp = nothing
%>