common handling of path param

From: Trolly Rogers <>
Date: Wed, 24 Feb 2010 21:51:00 -0500

Hi All - Hope I'm not being a pest. I just can't figure out how to handle
some common logic needing to be applied to a common path param (at least the
way I'd like to). I have a bunch of resources which all share a couple
things I mentioned below. There's basically one root resource, and a number
of sub-resources exposed via method and locator. Here's the two things they
all have in common...

1. part of thier URIs. They all begin with /users/{id}. The id is not the
user's user id exactly, but it is a unique way to identify the user and
provides a great piece of scoping info keeping my URIs RESTful.

2. The {id} path param needs to be checked against the value of
HttpServletRequest's getUserPrincipal().getName(). This name is set as part
of our security infrastructure and ensure the {id} passed to my resource is
in fact the right user.

I thought I was on to something when I was workin' on my own
ResourceFilterFactory impl. The thing I got hung up on was how to get the
value of the resolved {id} path param, is this possible in a

The solution I have working now is basically having my resource classes sub
class "UserIdAuthBasedResource" which provides a constructor forcing any sub
classes to pass in the user id and HttpServletRequest for the common
checking (#2). There's obvious disadvantages here (but it works), any