> May I know is there any tutorials/sample for “properties attribute”? I seem > not able to search any from the web. I have try to use the @Component > attribute “configurationPid” and get the properties value in “activate” > method through “Map<String, Object> config”, may I know is this the proper > way to retrieve configuration value? And what is the different between this > and the “properties” attribute?
Did you read http://enroute.osgi.org/services/org.osgi.service.component.html <http://enroute.osgi.org/services/org.osgi.service.component.html>? If you could not find the way how to use DS in that text, could you provide me with some feedback of what you miss so I can improve it for others? A trivial example that uses service properties: https://github.com/osgi/osgi.enroute.examples/blob/master/osgi.enroute.examples.component.application/src/osgi/enroute/examples/component/examples/EventListener.java <https://github.com/osgi/osgi.enroute.examples/blob/master/osgi.enroute.examples.component.application/src/osgi/enroute/examples/component/examples/EventListener.java> Kind regards, Peter Kriens > On 17 mei 2016, at 17:05, Timothy Ward <tim.w...@paremus.com> wrote: > > > >> On 17 May 2016, at 11:46, Chong, Kim Theng <kimtheng.ch...@experian.com >> <mailto:kimtheng.ch...@experian.com>> wrote: >> >> Hi Tim, >> >> Thank you very much for your explanation. >> >> Yes, we would like to use the standard annotations. >> >> and I am in the middle of trying the way that you mentioned in the >> “dependency injection” and I have some further questions: >> Register the other component in the service registry. If it is using a >> “private” (i.e. not exported) API then nobody else will find it. >> Does it means that, for the scenario when we want to inject >> “serviceRegistry” dependency to “myService”, we need to register both >> myService and serviceRegistry as @Component, and then use the @Reference >> annotation to reference “serviceRegistry” in “myService”? > > Yes - you need to register the “serviceRegistry” and then use @Reference to > consume it in “myService”. “myService” does not have to be registered as a > service for this to work, but it should be for the reset of your use case. > >> May I know is there any tutorials/sample for “properties attribute”? I seem >> not able to search any from the web. I have try to use the @Component >> attribute “configurationPid” and get the properties value in “activate” >> method through “Map<String, Object> config”, may I know is this the proper >> way to retrieve configuration value? And what is the different between this >> and the “properties” attribute? > > Defining an activate method using @Activate gives you a callback when all of > your components dependencies are satisfied, and the component is ready for > activation (read up on lazy activation if you’re interested in the difference > between these two things). > > Valid arguments to an activate method are zero or more of: > > Map<String, Object> - this will pass in a map of your component’s component > properties > A component property type - this is a type safe view of your component’s > component properties > BundleContext - this will pass in the BundleContext of the bundle which > defines the DS component > ComponentContext - this will pass the SCR ComponentContext for your component > > Using an Activate method is the only recommended way to retrieve component > properties in a DS component. > > Whey you set the properties attribute on the @Component annotation you are > providing a set of default keys and values that will be set in your > component’s component properties. The configuration pid that you’ve set is > used for integration with configuration admin. Configuration Admin can be > used to set or override component properties, and can also be used to limit a > component’s activation by using the configurationPolicy. > > You can see an example of using a type-safe component property type from the > OSGi IoT contest here: > > https://github.com/osgi/osgi.iot.contest.sdk/blob/master/osgi.enroute.trains.track.manager.example.provider/src/osgi/enroute/trains/track/manager/example/provider/ExampleTrackManagerImpl.java#L81 > > <https://github.com/osgi/osgi.iot.contest.sdk/blob/master/osgi.enroute.trains.track.manager.example.provider/src/osgi/enroute/trains/track/manager/example/provider/ExampleTrackManagerImpl.java#L81> > > https://github.com/osgi/osgi.iot.contest.sdk/blob/master/osgi.enroute.trains.api/src/osgi/enroute/trains/cloud/api/TrackConfiguration.java > > <https://github.com/osgi/osgi.iot.contest.sdk/blob/master/osgi.enroute.trains.api/src/osgi/enroute/trains/cloud/api/TrackConfiguration.java> > > Note that a component property type is defined as an annotation. This lets > you set default values, and ensures that only compatible types are used in > the configuration. > > Best Regards, > > > Tim Ward > > OSGi IoT Expert Group Chair > tim.w...@paremus.com <mailto:tim.w...@paremus.com> > > >> Thank you for your time. >> Best regards, >> Kim >> >> >> >> From: osgi-dev-boun...@mail.osgi.org <mailto:osgi-dev-boun...@mail.osgi.org> >> [mailto:osgi-dev-boun...@mail.osgi.org >> <mailto:osgi-dev-boun...@mail.osgi.org>] On Behalf Of Timothy Ward >> Sent: Monday, May 16, 2016 6:15 PM >> To: OSGi Developer Mail List >> Subject: Re: [osgi-dev] Question on dependencies injection and config >> reading in SCR >> >> Hi Kim, >> >> Declarative Services is a great choice, and should give you a simple way to >> do most of the things that you need. >> >> >> On 16 May 2016, at 04:52, Chong, Kim Theng <kimtheng.ch...@experian.com >> <mailto:kimtheng.ch...@experian.com>> wrote: >> >> Hi all, >> >> Previously we were using Spring DM to perform dependencies injections and >> services declaration, and now we would like to migrate to OSGI declarative >> services/SCR. May I know is there any ways to perform: >> >> 1. bean wiring/dependency injection for SCR like Spring DM does? For >> example: >> >> · @line1: We want to expose “myService” as a service. (This should >> be achievable by using @Component, @Service, correct me if I am wrong) >> >> Which annotation set are you using? The standard annotations do not have an >> @Service annotation, and I would very strongly suggest that you use the >> standard annotations. >> >> By default using @Component exports all of the directly implemented >> interfaces of your component class (i.e. the exact list of interfaces after >> the implements keyword). This can be modified using the service attribute of >> the annotation. >> >> >> · @line7: We want to inject “serviceRegistry” dependency to >> “myService”. >> · Note: “serviceRegistry” is a normal bean class, which does NOT >> expose as a service. >> >> <image002.png> >> >> This sort of injection (“private” components) is not supported by >> Declarative Services, however this isn’t really a problem. You can either: >> Register the other component in the service registry. If it is using a >> “private” (i.e. not exported) API then nobody else will find it. >> Just new up the instance in your activate method. If the serviceRegistry >> component really is a private detail of a single component then it’s just >> part of its behaviour. The new operator isn’t always evil! >> >> >> >> 2. Reading properties from a configuration file and binding them into >> service? For example >> >> a. There is a configuration file: service.config with following >> properties: >> >> # service type >> service.type = A >> >> >> And we are declaring the service such a way in Spring DM: (the service that >> going to be registered is based on the “service.type” value in the config >> file). >> Is this doable in OSGI declarative services? >> >> The @Component annotation has exactly this support using the properties >> attribute. >> >> Best of luck, >> >> Tim Ward >> >> Chief Technology Officer >> tim.w...@paremus.com <mailto:tim.w...@paremus.com> >> >> >> >> <image001.png> >> >> >> Thank you so much for your time. >> >> Best regards, >> Kim >> _______________________________________________ >> OSGi Developer Mail List >> osgi-dev@mail.osgi.org <mailto:osgi-dev@mail.osgi.org> >> https://mail.osgi.org/mailman/listinfo/osgi-dev >> <https://urldefense.proofpoint.com/v2/url?u=https-3A__mail.osgi.org_mailman_listinfo_osgi-2Ddev&d=DQMFaQ&c=BNNF-YNv0CLLslhP2Bcx5Q&r=nkTZHXrJs6ajcdXMiKMBUzIVqz19DiWDyUt7fOV9t7Y&m=cX5_qJ5tc0bDm5GylJHffQXTPGGWRqxn31k-Ekn21vU&s=cu2syswbxnkZ_zyepbVpXX5ieX8HY4XI1Aw6Al8foFQ&e=> >> >> _______________________________________________ >> OSGi Developer Mail List >> osgi-dev@mail.osgi.org <mailto:osgi-dev@mail.osgi.org> >> https://mail.osgi.org/mailman/listinfo/osgi-dev >> <https://mail.osgi.org/mailman/listinfo/osgi-dev> > _______________________________________________ > OSGi Developer Mail List > osgi-dev@mail.osgi.org <mailto:osgi-dev@mail.osgi.org> > https://mail.osgi.org/mailman/listinfo/osgi-dev > <https://mail.osgi.org/mailman/listinfo/osgi-dev>
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