利用xmlhttp和adodb.stream加缓存技术下载远程Web文件


            <%'----------远程获取内容，并将内容存在本地电脑上，包括任何文件！----------'---------------利用xmlhttp和adodb.stream-----------------'On Error Resume Next'-------------------------------定义输出格式-----------------------------path=request("path")if path ="" thenpath="http://pcqc.86516.com/index.asp"'这里定义的网址是百度，，注意一定要有文件后缀end if

sPath = Pathif left(lcase(path),7) <> "http://" then'-------------如果前面没有http就是本地文件，交给LocalFile处理------------LocalFile(path)else'--------------------否则为远程文件，交给RemoteFile处理------------------RemoteFile(Path)end if'Response.Write err.Description'--------------处理函数-----------

sub LocalFile(Path)'-------------------如果为本地文件则简单的跳转到该页面-------------------'Response.Redirect PathResponse.write "发生错误！"End SubSub RemoteFile(sPath)'-------------------------处理远程文件函数------------------------------FileName = GetFileName(sPath)'-------------GetFileName为把地址转换为合格的文件名过程-------------FileName = Server.MapPath("Cache/" & FileName)Set objFso = Server.CreateObject("Scripting.FileSystemObject")'Response.Write fileNameif objFso.FileExists(FileName) Then'--------------检查文件是否是已经访问过,如是，则简单跳转------------Response.Redirect "cache/" & GetFileName(path)Else'----------------否则的话就先用GetBody函数读取----------------------'Response.Write Patht = GetBody(Path)'-----------------用二进制方法写到浏览器上--------------------------Response.BinaryWrite tResponse.Flush'-----------------输出缓冲------------------------------------------SaveFile t,GetFileName(path)'------------------将文件内容缓存到本地路径，以待下次访问-----------End ifSet objFso = NothingEnd Sub

Function GetBody(url)'-----------------------本函数为远程获取内容的函数---------------------'on error resume next'Response.Write urlSet Retrieval = CreateObject("Microsoft.XMLHTTP")'----------------------建立XMLHTTP对象-----------------------------With Retrieval.Open "Get", url, False, "", ""'------------------用Get，异步的方法发送-----------------------.Send'GetBody = .ResponseTextGetBody = .ResponseBody'------------------函数返回获取的内容--------------------------End WithSet Retrieval = Nothing'response.Write err.DescriptionEnd Function

Function GetFileName(str)'-------------------------本函数为合格化的文件名函数-------------------str = Replace(lcase(str),"http://","")str = Replace(lcase(str),"//","/")str = Replace(str,"?","")str = Replace(str,"&","")str = Replace(str,"/","")str = replace(str,vbcrlf,"")GetFileName = strEnd Function

sub SaveFile(str,fName)'-------------------------本函数为将流内容存盘的函数-------------------'on error resume nextSet objStream = Server.CreateObject("ADODB.Stream")'--------------建立ADODB.Stream对象，必须要ADO 2.5以上版本---------'objStream.Type = adTypeBinaryobjStream.Type = 1'-------------以二进制模式打开-------------------------------------objStream.Openobjstream.write str'--------------------将字符串内容写入缓冲--------------------------'response.Write fname'路径注意objstream.SaveToFile "E:\webroot\pcqc\vip\UploadFile\cache\"&fName,2'objstream.SaveToFile "d:\cache\" & fName,adSaveCreateOverWrite'--------------------将缓冲的内容写入文件--------------------------'response.BinaryWrite objstream.Readobjstream.Close()set objstream = nothing'-----------------------关闭对象，释放资源-------------------------'response.Write err.DescriptionEnd sub

function saveimage(from,tofile)dim geturl,objStream,imgsgeturl=trim(from)imgs=gethttppage(geturl)'取得图片的具休内容的过程Set objStream = Server.CreateObject("ADODB.Stream")'建立ADODB.Stream对象，必须要ADO 2.5以上版本objStream.Type =1'以二进制模式打开objStream.Openobjstream.write imgs'将字符串内容写入缓冲objstream.SaveToFile server.mappath(tofile),2'-将缓冲的内容写入文件objstream.Close()'关闭对象set objstream=nothingend function%>