Stream Binary .ZIP to ASP Response

This ASP example demonstrates how to write a .zip to a temp directory, stream it to the ASP Response, and then delete the temporary .zip. From the end-user’s perspective, it looks like a simple .zip download.

It uses a freeware "Chilkat FileAccess" ActiveX which can be downloaded here: Freeware ASP FileAccess ActiveX Component.

<%
	
' Return a Zip file created from in-memory data.
set zip = Server.CreateObject("Chilkat.Zip2")
	
' This example will use the Chilkat FileAccess ActiveX, which is a free
' utility component available at:
' http://www.chilkatsoft.com/download/ChilkatFileAccess.zip
set fac = Server.CreateObject("Chilkat.FileAccess")
	
' Any value passed to UnlockComponent begins the 30-day trial.
unlocked = zip.UnlockComponent("30-day trial")
if unlocked then
	
	' Generate a temporary filename for the .zip to be created:
	dirPath = Server.MapPath("/data")
	prefix = "xyz"
	zipFilename = fac.GetTempFilename(dirPath,prefix)
	zip.NewZip zipFilename
	
	' If the files are large, the Zip component may use temporary files.
	' make sure your zip.TempDir property is set to a directory w/ read and write
	' permissions
	zip.TempDir = Server.MapPath("/data")
	
	' Add some directory trees to the zip object.
	recurse = 1
	baseDir = Server.MapPath("/temp/abc123/")
	' The MapPath returns a directory w/out the trailing slash
	baseDir = baseDir & "/*"
	count = zip.AppendFiles(baseDir,recurse)
	if count < 0 then
		Response.Write zip.LastErrorHtml
		Response.End
	end if
	
	baseDir = Server.MapPath("/temp/test111/")
	baseDir = baseDir & "/*"
	count = zip.AppendFiles(baseDir,recurse)
	if count < 0 then
		Response.Write zip.LastErrorHtml
		Response.End
	end if
	
	' Write the .zip file (to the filename used in the NewZip method )
	success = zip.WriteZipAndClose()
	if (success = 0) then
		Response.Write zip.LastErrorHtml
		Response.End
	end if
	
	' Send the .zip to the Response...
	' Use the Chilkat FileAccess ActiveX to stream it to the response output:
	
	' Open the file:
	' The integer arguments to FileOpen are identical to the arguments used
	' by the Microsoft CreateFile Platform SDK function
	' (http://msdn2.microsoft.com/en-us/library/aa363858.aspx)
	
	' Access Modes:
	' GENERIC_READ	(0x80000000)
	' GENERIC_WRITE (0x40000000)
	accessMode = &H80000000
	
	' Share Modes:
	' FILE_SHARE_READ(0x00000001)
	' FILE_SHARE_WRITE(0x00000002)
	shareMode = 1
	
	' Create Dispositions
	' CREATE_NEW          1
	' CREATE_ALWAYS       2
	' OPEN_EXISTING       3
	' OPEN_ALWAYS         4
	' TRUNCATE_EXISTING   5
	createDisp = 3
	
	' Attributes:
	' FILE_ATTRIBUTE_READONLY         0x00000001
	' FILE_ATTRIBUTE_HIDDEN           0x00000002
	' FILE_ATTRIBUTE_SYSTEM           0x00000004
	' FILE_ATTRIBUTE_DIRECTORY        0x00000010
	' FILE_ATTRIBUTE_ARCHIVE          0x00000020
	' FILE_ATTRIBUTE_NORMAL           0x00000080
	' FILE_ATTRIBUTE_TEMPORARY	   0x00000100
	fileAttr = 0
	
	success = fac.FileOpen(zipFilename,accessMode,shareMode,createDisp,fileAttr)
	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.
	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()
	
	' Delete the .zip we just created..
	success = fac.FileDelete(zipFilename)
end if
	
%>