How do I secure REST resources so that only a single user of a role can access it?

Question

I have succesfully created a REST web service with Jersey and secured it via java security annotations. It looks something like this

GET    /users/     // gives me all users
GET    /users/{id} // gives the user identified by {id}
POST   /users/     // creates user
PUT    /users/{id} // updates user identified by {id}
DELETE /users/{id} // delete user

I also have setup a realm with two roles: user and admin

I secured all methods so that only admins can access them.

Now i want to give free the PUT /users/{id} and GET /users/{id} methods, so that users can access their own and only their own resources.

Example:

// user anna is logged in and uses the following methods
    GET    /users/anna // returns 200 OK
    GET    /users/pete // returns 401 UNAUTHORIZED

Since i could not find a way to configure this through annotations, I am thinking of passing the HTTP request to the corresponding method to check if the user is allowed to access the resource.

It would look something like this for the GET /users/{id} method:

@GET
@Path("/users/{id}")
@RolesAllowed({"admin","user"})
@Produces(MediaType.APPLICATION_JSON)
public Response getUser(
    @PathParam("id") String id,
    @Context HttpServletRequest req
) {
    HttpSession session = request.getSession(false);

    if (session != null && session.getValue("userID").equals(id))
        return getObject(User.class, id);

    return Response.status(Status.UNAUTHORIZED).build();
}

I don't like this aproach because i think i would have to add the userID manualy to the session.

• Do you know a more elegant way to solve this?

• If not how do you add the userid to the session while using form authentication?

EDIT

Thank you Will and Pavel :) Here is my final solution:

@Context
private SecurityContext security;

// ...
@GET
@Path("/users/{id}")
@RolesAllowed({"admin","user"})
@Produces(MediaType.APPLICATION_JSON)
public Response getUser(@PathParam("id") String id){
    if (security.isUserInRole("user"))
        if (security.getUserPrincipal().getName().equals(id))
            return getObject(User.class, id);
        else
            return Response.status(Status.UNAUTHORIZED).build();
    else
        return getObject(User.class, id);
}