[jax-rs-spec users] [jsr339-experts] Re: Re: Re: UriTemplate API?

From: Santiago Pericas-Geertsen <>
Date: Mon, 25 Feb 2013 09:35:44 -0500

On Feb 22, 2013, at 11:02 AM, Sergey Beryozkin <> wrote:

> On 22/02/13 15:51, Bill Burke wrote:
>> On 2/22/2013 10:06 AM, Sergey Beryozkin wrote:
>>> On 22/02/13 14:55, Bill Burke wrote:
>>>> On 2/21/2013 12:37 PM, Marek Potociar wrote:
>>>>> On Feb 21, 2013, at 3:08 PM, Bill Burke <> wrote:
>>>>>> On 2/20/2013 12:08 PM, Marek Potociar wrote:
>>>>>>> Hello experts,
>>>>>>> Please review the issue that has been recently filed:
>>>>>>> In summary the user wants to be able take a URI template, e.g.
>>>>>>> "{name}/age/{age}" and then take a URI, e.g.
>>>>>>> "" (guess who...) and extract
>>>>>>> the
>>>>>>> parameter values information into a Map<String, String> instance.
>>>>>>> The solution may look like:
>>>>>>> UriBuilder builder
>>>>>>> = UriBuilder.fromUri("{name}/age/{age}");
>>>>>>> UriTemplate template = builder.template();
>>>>>>> Map<String, String> params = new HashMap<String, String>();
>>>>>>> if (template.match("",
>>>>>>> params)) {
>>>>>>> params.put("name", "Alois");
>>>>>>> URI uri = builder.buildFromMap(params);
>>>>>>> ...
>>>>>>> }
>>>>>>> The above requires following API changes:
>>>>>>> * introduce UriTemplate to represent, well, URI templates...
>>>>>>> * add ability to get UriTemplate instances from UriBuilder and
>>>>>>> WebTarget
>>>>>>> * expose the boolean UriTemplate.match(URI, Map<String,
>>>>>>> String>) method as part of the UriTemplate API.
>>>>>>> Now, finally, my question is:
>>>>>>> Q1. Do you think the above API would be useful?
>>>>>>> Q2. Is it something we should still try to add into JAX-RS 2.0, given
>>>>>>> where we are?
>>>>>> I'd say extend UriBuilder with a match() method instead of adding yet
>>>>>> another class we have to include within RuntimeDelegate. Something
>>>>>> like:
>>>>>> Map<String, String> match(String URI);
>>>>>> match() returns null if it can't match the current expression with
>>>>>> the passed in URI.
>>>>> Ok, your other email seems to make sense. Even though I think the user
>>>>> has a point (see issue comments) that the map should not be created by
>>>>> us, but user should be able to pass it as an input parameter. (Or
>>>>> maybe we can have 2 versions of the method.)
>>>>>> Useful. Yes. Include in JAX-RS 2.0? Well... I don't get've
>>>>>> deferred some pretty trivial improvements that I've submitted and in
>>>>>> some cases important JIRAs like:
>>>>>> JAX_RS_SPEC-339
>>>>>> JAX_RS_SPEC-317
>>>>>> But you want to include a brand new feature? Plus complain everytime
>>>>>> I make a suggestion that we're too close to the PFD? A bit
>>>>>> hypocritical don't you think?
>>>>> Maybe I should have just ignored this rant, but then again, it's rude
>>>>> to not reply to direct questions. :)
>>>>> Note that in my email I'm merely asking what you (EG) think. I'm not
>>>>> pushing for anything, or suggesting we should (or must) do anything.
>>>>> For that matter, I have not expressed any opinion about whether or not
>>>>> we should include the feature in 2.0. So to answer your last question,
>>>>> no, I do not think I'm being hypocritical here.
>>>>> Funny thing is that knowing you're somewhat frustrated after our
>>>>> recent conversations I tried to be extra careful to not sound like I
>>>>> would be pushing for anything and formulate the email as a pure
>>>>> summary of the issue at hand plus a couple of questions I'd like to
>>>>> get EG feedback on. Alas, apparently to no avail.
>>>> You are the spec lead. You're the one with deadlines. You decide when
>>>> you are closing feature requests. I don't care either way, but if the
>>>> spec is still open there are minor improvements I'd like to get in,
>>>> specifically the exception message stuff.
>>>> FWIW, I think the uri template stuff is a nice addition, but want new
>>>> methods on UriBuilder.
>>> I'm against turning UriBuilder into UriTemplate, it is way too complex
>>> already, and as I said it is *not* UriTemplate, but the 'user' of it
>> A uri template is something you build URIs from. Also, UriBuilder is
>> already a mutable uri template. UriBuilder already has code to parse and
>> process uri templates. Seems like a perfectly natural place to include
>> match to me.
> UriBuilder builds URI, asking URIBuilder "are you matching it" is confusing, because it is a builder, not a matcher. UriTemplate may have a number of useful methods letting users to get the properties of a given template - and having most of those methods would not make sense to have at UriBuilder level;

 I tend to agree with Sergey here. Matching is, in fact, a form of "deconstruction"; mixing this with "construction" isn't very clean. If it's about sharing code, that should be an implementation not an API issue.

-- Santiago