[weld-dev] Interceptors
Martin Kouba
mkouba at redhat.com
Mon May 18 02:34:41 EDT 2015
Dne 17.5.2015 v 00:02 Emily Jiang napsal(a):
> Thank you Martin! I think if I specifiy a class level interceptor,
> service(ServiceRequest, ServletResponse) will be intercepted but not
> doGet(), as doGet will be called by .service(ServletRequest,
> ServletResponse) directly not via a proxy. Did I miss anything?
>
Yes, the HttpServlet.doGet() invocation itself will not be intercepted,
but the interceptor will be called for the "outer" service() method. So
from the user point of view the result will be similar.
> On Fri, May 15, 2015 at 11:45 AM, Martin Kouba <mkouba at redhat.com
> <mailto:mkouba at redhat.com>> wrote:
>
> Dne 13.5.2015 v 00:27 Emily Jiang napsal(a):
>
> Thank you Jozef for the helpful info. I have another question on
> interceptor:
> EE7 spec states the JavaEE component classes, listed in Table
> EE.5-1,
> need to support interceptors. Take servlet for an example, which
> methods
> can be intercepted?
>
> As the servlet classes are invoked by the container, according
> to CDI1.2
> spec, it seems only service(ServletRequest, ServletResponse) can be
> intercepted. No other methods can be intercepted.
>
> Normally customer applications override doPost or doGet, but
> they cannot
> be intercepted. I cannot see any value of support interceptors on
> Servlet. Anything I missed?
>
>
> The serlet container always invokes Servlet.service(ServletRequest,
> ServletResponse)() which delegates to one of those convenient
> methods (doGet() etc.) in case of javax.servlet.http.HttpServlet. So
> if you extend HttpServlet and only override doGet() it would be
> "intercepted" if you annotate the servlet class with an interceptor
> binding. If you only annotate the doGet() method an interceptor will
> not be invoked.
>
>
> On Tue, May 12, 2015 at 7:50 AM, Jozef Hartinger
> <jharting at redhat.com <mailto:jharting at redhat.com>
> <mailto:jharting at redhat.com <mailto:jharting at redhat.com>>> wrote:
>
> On 05/11/2015 03:47 PM, Emily Jiang wrote:
>
>
> I have a few questions on interceptors:
>
> 1. CDI Interceptors on cdi beans
> Will the interceptors share the same creational context
> as the
> bean it is associated with?
>
> Yes. It is not the very same creational context but a new
> one with a
> parent-child relationship to the one of the associated
> bean. This is
> the same as for @Dependent dependencies
>
> Will Weld managed the cdi interceptors as well as the
> old-styled
> interceptors?
>
> Yes, Weld manages interceptor bindings associated using
> interceptor
> bindings as well as those associated using @Interceptors
>
> @Interceptors don't work on other cdi beans except ejb
> and managed
> beans, right?
>
> "Managed bean" is ambiguous. Weld support interceptors on
> all CDI
> managed beans (not on producer fields/methods nor
> extension-provided
> beans).
>
>
> 2. Interceptors on ejb beans or managed beans
> I think the integrator needs to create these
> @Interceptors and cdi
> interceptors.
>
> Yes, for EJBs and EE managed beans it is integrator's job
> to handle
> those. Weld can handle @AroundConstruct interceptors if
> needed. I've
> updated the docs on this topic recently:
> https://github.com/jharting/core/blob/a1eb6194be36ded86dc9709c6767f5016fb98997/docs/reference/src/main/asciidoc/ri-spi.asciidoc#around-construct-interception
>
> Will these interceptors use the non-contextual
> creational context
> (scope @Dependent) or use the ejb or managed bean's
> creational
> context?
>
> ejb or managed bean's creational context
>
>
> Will Weld destroy the interceptors when the associated
> beans are
> destroyed or the integrator need to destroy them? This
> logic
> applicable to both cdi interceptors and @Interceptors style
> interceptors, right?
>
> Any time the parent (bean's) creational context is
> destroyed, the
> children creational contexts (interceptors') are destroyed
> also by Weld.
>
>
> 3. Interceptors on JavaEE components
> I think this interceptors are created by Weld when the
> JavaEE
> component classes are created, right? By the way, how
> can the
> container make sure to destroy the interceptors?
>
> This depends on how the component classes are managed.
> Assuming the
> components are managed using Weld-provided InjectionTarget
> then it
> is up to the integrator to decide whether it provides
> interception
> support or whether it should be provided by Weld. This can be
> configured for each InjectionTarget individually using this
> builder:
> http://docs.jboss.org/weld/javadoc/2.2/weld-spi/org/jboss/weld/manager/api/WeldInjectionTargetBuilder.html
>
>
>
> --
> Thanks
> Emily
> =================
> Emily Jiang
> ejiang at apache.org <mailto:ejiang at apache.org>
> <mailto:ejiang at apache.org <mailto:ejiang at apache.org>>
>
>
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>
>
>
> --
> Thanks
> Emily
> =================
> Emily Jiang
> ejiang at apache.org <mailto:ejiang at apache.org>
> <mailto:ejiang at apache.org <mailto:ejiang at apache.org>>
>
>
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>
>
>
> --
> Thanks
> Emily
> =================
> Emily Jiang
> ejiang at apache.org <mailto:ejiang at apache.org>
--
Martin Kouba
Software Engineer
Red Hat, Czech Republic
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