Anne, thanks - but...
Any common OO API is then also 'well defined' because what I need technically is all right there in the method signatures (and it is even machine readable, too - of course). What is not in a common OO API is the order in which the methods are to be called - that 'additional semantic information' just gets hard coded in the client. But with SOAs the situation is exactly the same. There is nothing in the API definition that is machine readable and would provide information about the call order. So, how is moving the API description into an XML file any more 'well defined' than traditional OO API class definitions with method signatures? IMHO, the notion of well definedness of an API just doesn't hold as a distinguishing ... umm ... constraint ... between the SOA and the OO paradigm. Remaining confused... Jan On Feb 24, 2006, at 2:20 PM, Anne Thomas Manes wrote: > A well-defined interface is an interface that is defined using > standard interface description languages. The interface description > should be machine-readable so that code can be generated from it. A > comprehensive interface description should describe the location of > the service (or some means to find it), the protocol bindings > supported by the interface, the operations supported by the > service, the message formats that are exchanged with each > operation, any constraints and capabilities associated with the > interface, supported interchange patterns, and semantic information. > > > In web services, a comprehensive interface description would be > defined using XML Schema, WSDL, WS-Policy, WS-CDL, and RDF. > > A poorly-defined interface requires human communication to > determine the formats and protocols required to access the service. > > Anne > > On 2/23/06, Jan Algermissen <[EMAIL PROTECTED]> wrote: > SOAists, > > I keep reading about "consumers communicating with services through > *well defined interfaces*" as being one of the essential aspects of a > SOA. > > But I cannot figure out, what it means that an interface is "well > defined". Especially I do not understand what an interface is that is > *not* well defined. > > Can someone shed some light on this? > > Jan > > > ______________________________________________________________________ > __ > _______________ > Jan Algermissen, Consultant & Programmer > http://jalgermissen.com > Tugboat Consulting, 'Applying Web technology to enterprise IT' > http://www.tugboat.de > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > SPONSORED LINKS > Computer software Computer aided design software Computer job > Soa Service-oriented architecture > > YAHOO! GROUPS LINKS > > Visit your group "service-orientated-architecture" on the web. > > To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. > > ________________________________________________________________________ _______________ Jan Algermissen, Consultant & Programmer http://jalgermissen.com Tugboat Consulting, 'Applying Web technology to enterprise IT' http://www.tugboat.de Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/service-orientated-architecture/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
