I understood. It seems so. While this raise another question: Tuscany seemed skipped the 'composite' layer and direct access component service, then how to access services in two composites within same domain?
like this: -------------------------------------------------------------------- CompositeA.composite: <composite xmlns="http://www.osoa.org/xmlns/sca/1.0"; targetNamespace=http://www.globalfinance.com/NASDAQ"; name="NASDAQ"> <component name="StockQuoteServiceComponent"> <implementation.java class="com.ibm.stock.StockQuoteServiceImpl"/> </component> </composite> -------------------------------------------------------------------- CompositeB.composite: <composite xmlns="http://www.osoa.org/xmlns/sca/1.0"; targetNamespace=http://www.globalfinance.com/HongKong"; name="HongKong"> <component name="StockQuoteServiceComponent"> <implementation.java class="com.lenovo.stock.StockQuoteServiceImpl"/> </component> </composite> ------------------------------------------------------------------------------- When these two composite all loaded in one SCADomain. How do I get StockQuoteService supplied by CompositeB or CompositeA? How can SCADomain.getService(Class, String) handle such name conflict? ----- Original Message ----- From: "Jean-Sebastien Delfino" <[EMAIL PROTECTED]> To: <tuscany-dev@ws.apache.org> Sent: Wednesday, May 30, 2007 12:24 PM Subject: Re: (SCA)How can get the service by composite service name > Comments inline. > > Huang Kai wrote: >> Yes, the codes seems does so. >> But it's rather strange to access a service not by 'service name' exposed by >> compoiste, but by directly accessing component nested in a composite. >> > > Here's a little more info that will help explain that design: > > - When a composite is added to a domain, it is actually included in it, > so there is really no nesting. Components declared in the composite > become top level components as if they had been directly declared in the > composite describing the entire domain. This process is described in the > SCA assembly spec 1.0 in section 1.10.6.1: > 1.10.6.1 add To Domain-Level Composite > 3076 This functionality adds the composite identified by a supplied URI > to the Domain Level > 3077 Composite. The supplied composite URI must refer to a composite > within a installed contribution. > 3078 The composite's installed contribution determines how the > composite’s artifacts are resolved > 3079 (directly and indirectly). The supplied composite is added to the > domain composite with > 3080 semantics that correspond to the domain-level composite having an > <include> statement that > 3081 references the supplied composite. All of the composite’s > components become top-level > 3082 components and the services become externally visible services (eg. > they would be present in a > 3083 WSDL description of the domain). > > - Services offered by components in the composite become visible, and > can be addressed in a form consistent with what you would say in the > target of an SCA wire or reference, as described in section 1.6.4 of the > SCA assembly spec: > 1613 The reference element of a component and the reference element of a > service has a list > 1614 of one or more of the following wire-target-URI values for the > target, with multiple values > 1615 separated by a space: > 1616 • <component-name>/<service-name> > 1617 o where the target is a service of a component. The specification > of the service name > 1618 is optional if the target component only has one service with a > compatible interface > > As the spec says "the target is a service of a component". A service is > not really offered by a composite, it is offered by a component. A > composite service declaration is just a statement that a service offered > by a component should be promoted / made visible to the next level of > composition, when the particular composite is used as a (composite) > component implementation (using an <implementation.composite> element). > The service promoted by the composite service will then be offered by > that new component. > > Also, some components only offer one service for a given interface. In > that case you don't have to specify the service name, the component name > is sufficient to get the service matching the requested interface. > > So in your particular example: > - CalculatorServiceComponent is a top-level component. > - getService(CalculatorService.class, "CalculatorServiceComponent") is a > short form for getService(CalculatorService.class, > "CalculatorServiceComponent/CalculatorService"), you don't need to > specify the service name as CalculatorServiceComponent only provides one > service. > > Hope this helps. > >> ----- Original Message ----- >> From: "Simon Laws" <[EMAIL PROTECTED]> >> To: <tuscany-dev@ws.apache.org> >> Sent: Friday, May 25, 2007 10:03 PM >> Subject: Re: (SCA)How can get the service by composite service name >> >> >> >>> Hi Tony, >>> >>> I'm assuming you are using the sample CalculatorClient style code try to >>> access the service, i.e. the part that uses the scaDomain to get a local >>> reference to a component service. >>> >>> CalculatorService calculatorService = >>> scaDomain.getService(CalculatorService.class, >>> "CalculatorServiceComponent"); >>> >>> I just took a look at the code and currently the code behind this method >>> only looks at the components available in the domain composite when looking >>> for the named service, i.e. It's looking for a component and a service it >>> provides rather than a composite service that refers to a component service. >>> The term service is a little confusing in this regard in my opinion. >>> >>> Regards >>> >>> Simon >>> >> > > > > -- > Jean-Sebastien > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] >
