"Save As" from browser

Question

Basically, I'm trying to duplicate the functionality of this HTTP header:
Content-Type: application/octet-stream; Content-Disposition: attachment;
Except it has to be using pure client side technology.
Example: I have this link
<a href="file.txt>Save File As</a>
It needs to take file.txt and open the Save As dialog even though the Content-Type is text.  I am thinking of calling a tiny Java file that takes the txt file name as an argument, then opens the Save As dialog.
The HTTP headers are not an option because this will be used offline.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

Answer 1

I don't recall any tiny web servers in particular, but I've often stumbled across them and I'm sure if you Google or poke around on sourceforge you'll find a bunch. I'll bet you can find either free or cheap ones for major platforms, including Java. So maybe you could make/get one in Java, write wrappers that invoke it for Windows and OS X when the disk is inserted or clicked, plus a README file that just tells the user to double click the jar file, for other platforms. I'm sure that you'll find at least a skeleton for major languages (Python has one in its standard library, for example), and several complete servers as well. Apache would be overkill for this; but I'll bet you can find many tiny lightweight ones.
And web servers are pretty easy to write if you cut out 90% of the stuff that deals with high volume, security, the more obscure methods, etc. -- issues which wouldn't be relevant to a mini server that only has a single client. HTTP is well-documented and clean. I wrote a simple implementation of a server that just did GET (which is pretty much all you'd need) in Python in like a dozen lines of code (the one in the library, I couldn't use). Granted, Python is a terse language, but still... All you'd really need for this would be to support GET and the download headers. You'd probably want to support various caching headers so that you never read stuff off the CD twice (e.g., Last-Modified, If-Modified-Since). But really you'd almost certainly not have to bother with writing one; I'm sure you'll find an existing one that'll fit your needs.