On 10. Mar 2009, at 11:07, Paul Sandoz wrote:
> On Mar 9, 2009, at 8:03 PM, Jaka Jančar wrote:
>> On 9. Mar 2009, at 18:10, Paul Sandoz wrote:
>>
>> I can achieve it at Servlet level with either a custom servlet or a
>> servlet filter, but I'd have to manually be parsing resource URLs,
>> which I *REALLY* don't want. So that's why I want to do it *within*
>> JAX-RS boundaries.
>>
>> Any ideas? Pretty please? :)
>>
>
> You could obtain something from the servlet context that creates and
> manages the EntityManager instances. The filter can then cleanup
> those instances.
>
Yup, that solves the initialization nastiness, but it doesn't solve
cleanup nastiness. E.g. any exceptions thrown while commiting the
transaction get thrown outside JAX-RS and I have to manually build a
500 response, which should IMO always be Jersey's job.
> For a more elegant solution you will need to use something Jersey
> specific with resource specific filters, or use an IoC framework
> like Spring+AOP.
Hmm... resource specific filters. Looks _VERY_ interesting! I don't
like that it's not standard, but neither would be my own
implementation, so I might as well use it. And perhaps it one day
becomes standard :)
It seems this would also solve the above problem with exceptions
during cleanup.
I have a couple of questions regarding resource specific filters:
1)
I'm looking at WebApplicationImpl and HttpMethodRule but am not
entirely sure about the order of the execution of the filters.
For example, when doing GET /first/second/third:
- FirstResource.getSecondResource() (@Path("/second"))
- SecondResource.getThirdResource() (@Path("/third"))
- ThirdResource.handleGet() (@GET)
Would this be the order of calls with filters added:
- FirstResourceRequestFilter.filter()
- FirstResource.getSecondResource()
- SecondResourceRequestFilter.filter()
- SecondResource.getThirdResource()
- ThirdResourceRequestFilter.filter()
- ThirdResource.handleGet()
- FirstResourceResponseFilter.filter();
- SecondResourceResponseFilter.filter();
- ThirdResourceResponseFilter.filter();
If so, is there a way to reverse the Response filters?
2)
Will Resource(Request|Response)Filters be added for resource classes
annotated with @ResourceFilters which I instantiate myself in sub-
resource locators?
If so, will multiple instances of the resource filter be added for
multiple instances of the resource? That is, would request "GET /
resource-of-class-a/resource-of-class-b/resource-of-class-a" add two
instances of the filter defined for the class A? (this I don't
actually need, but am just curious)
If so (heheh), is it possible for the resource specific filter
instance to know because of which resource instance it was created?
Thanks again, you've been extraordinarily helpful!
Jaka