Isn't this issue related to JAX_RS_SPEC-35 [1]? See also the
originating thread [2] on the Jersey users list.
[1]
http://java.net/jira/browse/JAX_RS_SPEC-35
[2]
http://jersey.576304.n2.nabble.com/injecting-Context-fields-on-sub-resources-td4930958.html#a4930958
On 3/9/11 9:35 AM, Adam Bien wrote:
> On 09.03.2011, at 16:41, Bill Burke wrote:
>
>> The problem is that he wants to inject information about the sub resource into the creation of the EJB.
> And this is a huge problem. It happens in every non-trivial application.
>
>> You can't use a pojo or entity because you may want to do transactions within the subresource (or other functions that EJB provides).
> And injection. If you are using a POJO it cannot be even a CDI managed bean.
>> Adam, are you sure the new EJB singleton beans wouldn't allow for this?
> Singleton would work - but then you will get concurrency issues (=bottlenecks). If you make them BeanManagedConcurrency you will get consistencies issue. @Stateful would not work as well.
>
> The simplest possible solution would be something like:
>
> @Stateless
> public SubResource{
>
> @PathParam
> long id;
>
> }
>
> or the injection of a more generic "JAX-RS" context into EJB / CDI bean.
>
>
>
>
>>
>> On 3/9/11 10:05 AM, Marek Potociar wrote:
>>> Hi Adam,
>>> I am still not sure I fully follow the problem being described. Could you please provide a code snippet(s) that demonstrate:
>>> 1. what is the current problem
>>> 2. example of a desired solution that solves 1.
>>>
>>> Many thanks,
>>> Marek
>>>
>>> On 03/08/2011 09:02 PM, Adam Bien wrote:
>>>> Hi Markus
>>>>
>>>> please see inline comments:
>>>>
>>>> On 08.03.2011, at 18:38, Markus KARG wrote:
>>>>
>>>>> Seems like I'm a bit slow on the uptake today... ;-) Can you post a short
>>>>> snippet of what you try to achieve and what the exact problem is? I mean,
>>>>> you can just create a new object inside the sub-resource locator and pass a
>>>>> path param as the PK into the constructor manually (or use it as a JPA query
>>>>> criteria), which both is rather short and simple.
>>>>>
>>>>> @GET @Path("{pk}")
>>>>> public Pojo getPojo(@PathParam("pk") T pk) {
>>>>> return new Pojo (pk);
>>>>> }
>>>> Works and is o.k.
>>>>> @EJB SB sb;
>>>>> @GET @Path("{pk}")
>>>>> public SB getSb(@PathParam("pk") T pk) {
>>>>> sb.setPk(pk);
>>>>> return sb;
>>>>> }
>>>> It doesn't work - you cannot maintain client-specific state in a Stateless Session bean. You will need to pass the context in different way.
>>>> One possibility would be to inject a JAX-RS context into an EJB and fetch the current id from that.
>>>>
>>>>> @GET @Path("{pk}")
>>>>> public Entity getEntity(@PathParam("pk") T pk) {
>>>>> return em.find(Entity.class, pk);
>>>>> }
>>>> Works of course.
>>>>> How would you like the solution to look like in terms of Java syntax? Maybe
>>>>> we then see more clear the elegance you expect.
>>>> Passing parameters from JAX-RS to stateless session beans as sub-resource locators is the problem. It happens in all non-trivial applications.
>>>> You could use POJOs, but then you will need another transactional layer or implement transactions buy yourself..
>>>>
>>>> thanks for the code! :-),
>>>>
>>>> adam
>>>>> Regards
>>>>> Markus
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Adam Bien [mailto:abien_at_adam-bien.com]
>>>>>> Sent: Montag, 7. März 2011 20:36
>>>>>> To: jsr339-experts_at_jax-rs-spec.java.net
>>>>>> Subject: [jsr339-experts] Re: First steps
>>>>>>
>>>>>> In sub-resource locator you are usually passing an URI (from
>>>>>> @PathParam).
>>>>>> There is no elegant way right now to implement that with EJB 3.1.
>>>>>>
>>>>>> With POJOs it is not a big problem - you can pass the URI (usually a
>>>>>> PK) in a constructor...
>>>>>>
>>>>>> Constructor injection of the current context would be nice...
>>>>>>
>>>>>> thanks!,
>>>>>>
>>>>>> adam
>>>>>>
>>>>>>
>>>>>> On 07.03.2011, at 14:57, Bill Burke wrote:
>>>>>>
>>>>>>>
>>>>>>> On 3/6/11 4:00 AM, Adam Bien wrote:
>>>>>>>> Hi Roberto,
>>>>>>>>
>>>>>>>> better intergration with EJB 3.2 would be also nice. E.g. it is hard
>>>>>> right now to use EJB 3.2 as a sub-resource.
>>>>>>>
>>>>>>> @EJB Sub sub;
>>>>>>>
>>>>>>> @Path("sub")
>>>>>>> public Sub getSub() { return sub; }
>>>>>>>
>>>>>>> ?
>>>>>>>
>>>>>>> --
>>>>>>> Bill Burke
>>>>>>> JBoss, a division of Red Hat
>>>>>>> http://bill.burkecentral.com
>>>>>
>>>>
>> --
>> Bill Burke
>> JBoss, a division of Red Hat
>> http://bill.burkecentral.com
>>
>