Question: I want a `/plan` method to return a json object that's itself returned by another local (but belonging to another web app in java) URL (let's call it `/plan2` for the sake of this question). 

What I want is not a redirect but really to have `/plan` return the data **as it is returned** by `/plan2`, to which I'm appending a bunch of other keys. Since the request is local, would using `Net::HTTP` be overkill? What are my options, considering I'd also like to send an HTTP Accept header along.

Answer: 
Shooting in the dark here, but I am assuming that `/plan` belongs to public Rails app and the `/plan2` is the url from **another web app** (maybe not even Rails) on the same server accessible by Rails app but not publicly available. If this is the case, then yes, you can get the response, but I would suggest rather [OpenURI](http://www.ruby-doc.org/stdlib-1.9.3/libdoc/open-uri/rdoc/OpenURI.html) or [Mechanize](https://github.com/tenderlove/mechanize/) than `Net::HTTP`. If you put it in `respond_to` JSON format block then everything should be fine with `Accept` header also.
are you speaking of re-using functionality of another controller-method?

there is no standard way of doing this in rails. you could either put the common functionality into a module and include it this way, or use inheritance if the functionality is in another controller. if it's the same controller class, you could just call the method.

if it's a "private" url, how are you going to call it via http?!