what is a good web app platform to build a VERY simple, single-purpose PDF "sign maker"

We need something very trivial, yet apparently impossible to do with Rails...there is no full featured PDF library for ruby yet.

What I need to build is very simple:

• Web app, ideally hostable on Heroku or Godaddy
• ONE url: url specifies an existing PNG graphic file + a text string + an X,Y offset
• creates a PDF that simply overlays the text string (at X,Y) on top of the graphic

That's it, just a quick and dirty "sign customizer" to slap a string of text at a precise l开发者_如何学Cocation on top of a graphic.

iText for Java is a nice library that does everything, but I don't know where to start to build a server-side Java web app... or to be more accurate, when I googled doing that my reaction was "is it really THAT complicated to deploy a web app using Java?" (spoiled by Rails I guess).

Any tips would be appreciated... it's an important function for my app that I'm disappointed to have to build outside by Rails app, but until there's a good PDF library for ruby I guess I'll have to learn a different way to do this!

For anyone who has a similar issue with ruby not handling pdf, an update: so far we've had great initial success with PHP + FPDF from http://www.fpdf.org/

The docs and tutorials for fpdf are awesome.