The configuration is meant to be rather stable. I don't intend to change the configuration back and forth in runtime. However, it makes it possible for me to customze the requirements for different installations (and for different customers).
The dependency is set to optional. I also made the method that updates the filter "synchronized" since I did detect some concurrency problems at first. /Bengt 2012/11/28 Clement Escoffier <[email protected]> > Hi, > > > > On 28 nov. 2012, at 15:33, Bengt Rodehav <[email protected]> wrote: > > > Thanks again - it worked fine. > > > > Great ! > > > Do you think this a bad idea (The "May lead to fun cases" got me a little > > worried)? > > > > What I'm doing is making my filter dynamic. In this case a configuration > > property is used to wire my service against the appropriate service > > providers. The service providers expose a list of "qualifiers" (as > service > > properties) that they support. The service consumer specifies a > "qualifier" > > that is required. By dynamically setting the filter I can change the > > service consumers service requirements dynamically in runtime. > > > > There is a couple of things that can happen: > - if you touch the dependency in the same thread as the filter update, the > provider set won't change for the current thread (others will be updated) > - if you change the filter and the instance becomes invalid, you will have > issues if you try to access (untouched) dependency within the same thread. > > I would advise to set the dependency optional to avoid the last issue. > > Regards, > > Clement > > > > /Bengt > > > > > > 2012/11/28 Clement Escoffier <[email protected]> > > > >> Hi, > >> > >> Are you trying to modify your own filter ? May lead to fun cases :-) > >> > >> In that case: > >> > >> InstanceManager me = (InstanceManager) ((Pojo) > >> this).getComponentInstance(); > >> > >> > >> Explanations: > >> - each iPOJO instance is implementing a org.apache.felix.ipojo.Pojo > >> interface > >> - so implements the getComponentInstance method returning a > >> ComponentInstance > >> - you cast the ComponentInstance to InstanceManager and you're back on > >> track > >> > >> Regards, > >> > >> Clement > >> > >> > >> On 28 nov. 2012, at 14:19, Bengt Rodehav <[email protected]> wrote: > >> > >>> Sorry for bothering you again.... > >>> > >>> I use iPOJO annotations like this: > >>> > >>> * @Component(name = "componentName", propagation = true, immediate = > >> true)* > >>> * @Provides* > >>> * public class MyClass {* > >>> > >>> > >>> I tried the following cast: > >>> > >>> * InstanceManager im = (InstanceManager) this;* > >>> > >>> where "this" is an instance of MyClass. The cast doesn't work since > >>> MyClass is not a sub class of InstanceManager. How do I get hold of a > >>> component instance? > >>> > >>> /Bengt > >>> > >>> > >>> > >>> > >>> 2012/11/28 Bengt Rodehav <[email protected]> > >>> > >>>> Thanks a lot, will try this approach. > >>>> > >>>> /Bengt > >>>> > >>>> > >>>> 2012/11/28 Clement Escoffier <[email protected]> > >>>> > >>>>> Hi, > >>>>> > >>>>> The DependencyModel is the parent class of all the iPOJO's service > >>>>> dependencies. So, the easiest way is to access to your service > >> dependency: > >>>>> > >>>>> InstanceManager im = (InstanceManager) componentInstance; > >>>>> DependencyHandler handler = > >>>>> im.getHandler("org.apache.felix.ipojo:requires"); > >>>>> Dependencies[] deps = handler.getDependencies(); > >>>>> // Lookup your dependency from deps (by id, by specification…) > >>>>> dep.setFilter(filter); > >>>>> > >>>>> Regards, > >>>>> > >>>>> Clement > >>>>> > >>>>> > >>>>> > >>>>> > >>>>> On 28 nov. 2012, at 13:09, Bengt Rodehav <[email protected]> wrote: > >>>>> > >>>>>> Thanks for you reply Clement, > >>>>>> > >>>>>> So, the following should work (in principal)? > >>>>>> > >>>>>> * @Property(name = "myProperty" mandatory = true)* > >>>>>> * public void setMyPropertey(String theProperty) {* > >>>>>> * // Calculate new filter based on myProperty* > >>>>>> * String filter = ....* > >>>>>> * > >>>>>> * > >>>>>> * // How do I get an instance of "DependencyModel"?* > >>>>>> * DependencyModel.setFilter(filter);* > >>>>>> * }* > >>>>>> > >>>>>> I've never used the DependencyModel class before. How do I gain > access > >>>>> to > >>>>>> the correct instance? What maven artifact do I need for this? > >>>>>> > >>>>>> /Bengt > >>>>>> > >>>>>> > >>>>>> 2012/11/28 Clement Escoffier <[email protected]> > >>>>>> > >>>>>>> Hi, > >>>>>>> > >>>>>>> Using the iPOJO API you can use 'setFilter' to update the LDAP > filter > >>>>> of a > >>>>>>> dependency (DependencyModel.setFilter). When changed the set of > bound > >>>>>>> services is recomputed. Be aware that it may lead to an > invalidation > >>>>> of the > >>>>>>> instance if no providers match the new filter. > >>>>>>> > >>>>>>> What we did in the past is to develop a handler receiving the new > >>>>>>> properties, computing the new filter and applying it to the > targeted > >>>>>>> dependency. > >>>>>>> > >>>>>>> Regards, > >>>>>>> > >>>>>>> Clement > >>>>>>> > >>>>>>> On 27 nov. 2012, at 11:41, Bengt Rodehav <[email protected]> > wrote: > >>>>>>> > >>>>>>>> I'm using the latest iPOJO version. I'm trying to use > configuration > >>>>>>>> properties (via config admin) to make my service wiring dynamic. > >>>>>>>> > >>>>>>>> I have handler services that expose service properties (that tells > >> the > >>>>>>>> world what they can handle). The consumer of these services uses > >>>>> @Require > >>>>>>>> with an LDAP filter to specify what needs to be handled and thus > >> limit > >>>>>>> what > >>>>>>>> handlers can be used. > >>>>>>>> > >>>>>>>> But, I want the LDAP filter to be dynamic so that I can wire up > >>>>> service > >>>>>>>> providers with service consumers by configuration properties on > the > >>>>>>>> consumers and providers. > >>>>>>>> > >>>>>>>> I've tried to buld the LDAP filter dynamically (using a > configurable > >>>>>>>> property) but I get the compilation error: > >>>>>>>> > >>>>>>>> * The value for annotation attribute Requires.filter must be a > >>>>> constant > >>>>>>>> expression* > >>>>>>>> > >>>>>>>> I was hoping that if I changed a configuration property, iPOJO > would > >>>>>>>> refresh its list of provider services to match the changed LDAP > >>>>> filter. > >>>>>>>> > >>>>>>>> How can I accomplish what I want? Is there a best practice? > >>>>>>>> > >>>>>>>> /Bengt > >>>>>>> > >>>>>>> > >>>>>>> > --------------------------------------------------------------------- > >>>>>>> To unsubscribe, e-mail: [email protected] > >>>>>>> For additional commands, e-mail: [email protected] > >>>>>>> > >>>>>>> > >>>>> > >>>>> > >>>>> --------------------------------------------------------------------- > >>>>> To unsubscribe, e-mail: [email protected] > >>>>> For additional commands, e-mail: [email protected] > >>>>> > >>>>> > >>>> > >> > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: [email protected] > >> For additional commands, e-mail: [email protected] > >> > >> > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
