This blog post shows how to stream a binary file to the ASP Response. It could be a MS-Word document, PDF, .zip, etc. This code becomes necessary if the server-side ASP is generating a file on-the-fly for the user to download.
Note: There are many examples on the Web that demonstrate how to use ADODB.Stream to send binary files to the browser. However, the drawback is that you must first load the entire file into memory (on the web server) before streaming to output. This solution is better because it truly streams — reading and writing a chunk at a time.
<%
' This example demonstrates how to stream a binary file to the ASP Response.
set fac = Server.CreateObject("Chilkat_9_5_0.FileAccess")
' The Chilkat FileAccess ActiveX can stream a binary file to the ASP Response output:
success = fac.OpenForRead(Server.MapPath("/data/abc123.zip"))
if (success = 0) then
Response.Write fac.LastErrorHtml
Response.End
end if
' Send the response header.
' The filename that the end-user will see is specified in the Content-Disposition header.
' The Response.ContentType should be set according to the type of file.
' (see the list of content types below)
Response.Buffer = True
Response.Expires = 0
Response.ContentType = "application/zip"
Response.AddHeader "Content-transfer-encoding", "binary"
Response.AddHeader "Content-Disposition", "attachment;filename=test.zip"
' Stream the file to the output:
Dim dataChunk
do while (fac.EndOfFile = 0)
' Read chunks of 4K at a time...
dataChunk = fac.FileRead(4096)
if (not (isNull(dataChunk))) then
Response.BinaryWrite(dataChunk)
Response.Flush()
end if
loop
fac.FileClose
Response.Flush()
%>
Here is a list of common content-types according to filename extension:
.abs: audio/x-mpeg
.ai: application/postscript
.aif: audio/x-aiff
.aifc: audio/x-aiff
.aiff: audio/x-aiff
.aim: application/x-aim
.art: image/x-jg
.wmv: video/x-ms-wmv
.asf: video/x-ms-asf
.asx: video/x-ms-asf
.au: audio/basic
.avi: video/x-msvideo
.avx: video/x-rad-screenplay
.bcpio: application/x-bcpio
.bin: application/octet-stream
.bmp: image/bmp
.body: text/html
.cdf: application/x-cdf
.cer: application/x-x509-ca-cert
.class: application/java
.cpio: application/x-cpio
.csh: application/x-csh
.css: text/css
.dib: image/bmp
.doc: application/msword
.dtd: text/plain
.dv: video/x-dv
.dvi: application/x-dvi
.eps: application/postscript
.etx: text/x-setext
.exe: application/octet-stream
.gif: image/gif
.gtar: application/x-gtar
.gz: application/x-gzip
.hdf: application/x-hdf
.hqx: application/mac-binhex40
.htc: text/x-component
.htm: text/html
.html: text/html
.hqx: application/mac-binhex40
.ief: image/ief
.jad: text/vnd.sun.j2me.app-descriptor
.jar: application/java-archive
.java: text/plain
.jnlp: application/x-java-jnlp-file
.jpe: image/jpeg
.jpeg: image/jpeg
.jpg: image/jpeg
.js: text/javascript
.kar: audio/x-midi
.latex: application/x-latex
.m3u: audio/x-mpegurl
.mac: image/x-macpaint
.man: application/x-troff-man
.me: application/x-troff-me
.mid: audio/x-midi
.midi: audio/x-midi
.mif: application/x-mif
.mov: video/quicktime
.movie: video/x-sgi-movie
.mp1: audio/x-mpeg
.mp2: audio/x-mpeg
.mp3: audio/x-mpeg
.mpa: audio/x-mpeg
.mpe: video/mpeg
.mpeg: video/mpeg
.mpega: audio/x-mpeg
.mpg: video/mpeg
.mpv2: video/mpeg2
.ms: application/x-wais-source
.nc: application/x-netcdf
.oda: application/oda
.pbm: image/x-portable-bitmap
.pct: image/pict
.pdf: application/pdf
.pgm: image/x-portable-graymap
.pic: image/pict
.pict: image/pict
.pls: audio/x-scpls
.png: image/png
.pnm: image/x-portable-anymap
.pnt: image/x-macpaint
.ppm: image/x-portable-pixmap
.ps: application/postscript
.psd: image/x-photoshop
.qt: video/quicktime
.qti: image/x-quicktime
.qtif: image/x-quicktime
.ras: image/x-cmu-raster
.rgb: image/x-rgb
.rm: application/vnd.rn-realmedia
.roff: application/x-troff
.rtf: application/rtf
.rtx: text/richtext
.sh: application/x-sh
.shar: application/x-shar
.smf: audio/x-midi
.snd: audio/basic
.src: application/x-wais-source
.sv4cpio: application/x-sv4cpio
.sv4crc: application/x-sv4crc
.swf: application/x-shockwave-flash
.t: application/x-troff
.tar: application/x-tar
.tcl: application/x-tcl
.tex: application/x-tex
.texi: application/x-texinfo
.texinfo: application/x-texinfo
.tif: image/tiff
.tiff: image/tiff
.tr: application/x-troff
.tsv: text/tab-separated-values
.txt: text/plain
.ulw: audio/basic
.ustar: application/x-ustar
.xbm: image/x-xbitmap
.xpm: image/x-xpixmap
.xwd: image/x-xwindowdump
.wav: audio/x-wav
.wbmp: image/vnd.wap.wbmp
.wml: text/vnd.wap.wml
.wmlc: application/vnd.wap.wmlc
.wmls: text/vnd.wap.wmls
.wmlscriptc: application/vnd.wap.wmlscriptc
.wrl: x-world/x-vrml
.Z: application/x-compress
.z: application/x-compress
.zip: application/zip
.xml: text/xml
