The problem is that he wants to inject information about the sub
resource into the creation of the EJB. You can't use a pojo or entity
because you may want to do transactions within the subresource (or other
functions that EJB provides).
Adam, are you sure the new EJB singleton beans wouldn't allow for this?
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