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• factorySet: The component factory ID. By default, a Service component is automatically instantiated as a singleton when the bundle is started, and when all required dependencies are satisfied. But when a component must be created, configured, or disposed dynamically, and when multiple instances of the same component are needed, a factorySet should be used. When you use this attribute, a java.util.Set<Dictionary> object is registered into the OSGi regitry, with a specific dm.factory.name property matching the ID you specify in the attribute. This Set<Dictionary> will act as a Factory API, and another component may define a dependency on this Set and add some configuration dictionaries in it, in order to fire some component instantiation/activation. There is one component instantiated per added dictionary, which is passed to component instances via a configurable callback method (using the factoryConfigure attribute). All public properties will be propagated along with eventual published service. A public property is a property which does not start with a dot ("."). Properties starting with a dot are considered private to the component, and won't be propagated to published service. This model is actually similar to the Declarative Service "Component Factories" concept, except that you don't have a dependency on a specific API, but rather on a basic jdk class (java.util.Set<Dictionary>). Notice that, unlike in Declarative Service, the component factory is  is provided once the component bundle is started, even if required dependencies are not satisfied. This is useful when the component want to dynamically configure its dependency filters. So, to summarize:
  • Each time a new Dictionary is added into the Set, then a new instance of the annotated component will be instantiated, and this dictionary is passed to the component callback specified with the factoryConfigure attribute.
  • Each time an existing Dictionary is re-added into the Set, then the corresponding component instance is updated, and the updated dictionary is also passed to the callback specified in the factoryConfigure attribute.
  • Each time an existing Dictionary is removed from the Set, then the corresponding component instance will be stopped and destroyed.

• factoryConfigure: Sets the "configure" callback method name to be called with the factory configuration. This attribute only makes sense if the factorySet() attribute is used. If specified, then this attribute references a component callback method, which is called for providing the configuration supplied by the factory that instantiated this Servicecomponent. The current Service properties will be also updated with all public properties (which don't start with a dot).

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 /**
   * This component will be activated once the bundle is started and when all required dependencies
   * are available.
   */
 @Component
 class X implements Z {
     @ConfigurationDependency(pid="MyPid")
     void configure(Dictionary conf) {
          // Configure or reconfigure our service.
     }

     @Start
     void start() {
         // Our Servicecomponent is starting and is about to be registered in the OSGi registry as a Z service.
     }

     public void doService() {
         // ...
     }
 }

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