Hi Hoss,
Thanks for the pointers, and sorry, it was a bug in my code (was some dead code
which was alphabetizing the facet link text and also the parameters themselves
indirectly by reference).
I actually ended up building a servlet and a component to print out the
multi-valued parameters using HttpServletRequest.getParameterValues("myparam")
and ResponseBuilder.req.getParams().getParams("myparam") respectively to
isolate the problem. Both of them returned the parameters in the correct order.
So I went trolling through the code with a debugger, to observe exactly at what
point the order got messed up, and found the bug.
FWIW, I am using Tomcat 5.5.
Thanks to everybody for their help, and sorry for the noise, guess I should
have done the debugger thing before I threw up my hands :-).
-sujit
On Mar 19, 2012, at 6:55 PM, Chris Hostetter wrote:
>
> : I have a custom component which depends on the ordering of a
> : multi-valued parameter. Unfortunately it looks like the values do not
> : come back in the same order as they were put in the URL. Here is some
> : code to explain the behavior:
> ...
> : and I notice that the values are ordered differently than ["foo", "bar",
> : "baz"] that I would have expected. I am guessing its because the
> : SolrParams is a MultiMap structure, so order is destroyed on its way in.
>
> a) MultiMapSolrParams does not destroy order on the way in
> b) when dealing with HTTP requests, the request params actaully use an
> instance of ServletSolrParams which is backed directly by the
> ServletRequest.getParameterMap() -- you should get the values returned in
> the exact order as ServletRequest.getParameterMap().get("myparam")
>
> : 1) is there a setting in Solr can use to enforce ordering of
> : multi-valued parameters? I suppose I could use a single parameter with
> : comma-separated values, but its a bit late to do that now...
>
> Should already be enforced in MultiMapSolrParams and ServletSolrParams
>
> : 2) is it possible to use a specific SolrParams object that preserves order?
> If so how?
>
> see above.
>
> : 3) is it possible to get a reference to the HTTP request object from within
> a component? If so how?
>
> not out of the box, because there is no garuntee that solr is even running
> in a servlet container. you can subclass SolrDispatchFilter to do this if
> you wish (note the comment in the execute() method).
>
> My questions to you...
>
> 1) what servlet container are you using?
> 2) have you tested your servlet
> container with a simple servlet (ie: eliminate solr from the equation) to
> verify that the ServletRequest.getParameterMap() contains your request
> values in order?
>
>
> if you debug this and find evidence that something in solr is re-ordering
> the values in a MultiMapSolrParams or ServletSolrParams *PLEASE* open a
> jira with a reproducable example .. that would definitley be an anoying
> bug we should get to the bottom of.
>
>
> -Hoss
