利用adodb.stream直接下载任何后缀的文件(防盗链)

网络整理 - 09-14

原作:possible_Y,载自时代课堂

在浏览器的地址栏里直接输入一个doc或xls或jpg的文件的url路径，那么该文件会直接显示在浏览器里。而在很多时候我们希望能直接弹出下载提示框让用户下载，我们该怎么办呢？这里有两种方法：
1、设置你的服务器的iis，给doc等后缀名做映射
2、在向客户端发送时设置其contenttype

下面详细说明方法2

<%
Response.Buffer = true
Response.Clear

dim url
Dim fso,fl,flsize
dim Dname
Dim objStream,ContentType,flName,isre,url1
'*********************************************调用时传入的下载文件名
Dname=trim(request("n"))
'******************************************************************
If Dname<>"" Then
'******************************下载文件存放的服务端目录
url=server.MapPath("http://www.cuoxin.com/")&"\"&Dname
'***************************************************
End If

Set fso=Server.CreateObject("scripting.FileSystemObject")
Set fl=fso.getfile(url)
flsize=fl.size
flName=fl.name
Set fl=Nothing
Set fso=Nothing
%>
<%
Set objStream = Server.CreateObject("ADODB.Stream")
objStream.Open
objStream.Type = 1
objStream.LoadFromFile url

Select Case lcase(Right(flName, 4))
Case ".asf"
   ContentType = "video/x-ms-asf"
Case ".avi"
   ContentType = "video/avi"
Case ".doc"
   ContentType = "application/msword"
Case ".zip"
   ContentType = "application/zip"
Case ".xls"
   ContentType = "application/vnd.ms-excel"
Case ".gif"
   ContentType = "image/gif"
Case ".jpg", "jpeg"
   ContentType = "image/jpeg"
Case ".wav"
   ContentType = "audio/wav"
Case ".mp3"
   ContentType = "audio/mpeg3"
Case ".mpg", "mpeg"
   ContentType = "video/mpeg"
Case ".rtf"
   ContentType = "application/rtf"
Case ".htm", "html"
   ContentType = "text/html"
Case ".txt"
   ContentType = "text/plain"
Case Else
   ContentType = "application/octet-stream"
End Select

Response.AddHeader "Content-Disposition", "attachment; filename=" & flName
Response.AddHeader "Content-Length", flsize

Response.Charset = "UTF-8"
Response.ContentType = ContentType

Response.BinaryWrite objStream.Read
Response.Flush
response.Clear()
objStream.Close
Set objStream = Nothing

将下面的东西存成download.asp然后你就可以用<a herf="http://www.knowsky.com/download.asp?n=file.doc">download!