CIS 764 Database Systems EngineeringSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Fall 2008http://www.cis.ksu.edu1CIS 764 Database Systems EngineeringL15 Web Services ++ Web service as an enterprise “component”; Business process specificationFall 2008http://www.cis.ksu.edu2CIS 764 Database Systems EngineeringPrevious (middleware model) -- * business method ( or data access) exposed as an object * single methods specified via assertions; single method behavior represented via sequence model - coordination of methods == business process … not yet addressedFall 2008http://www.cis.ksu.edu3CIS 764 Database Systems EngineeringPrevious (middleware model) -- ?? How related to DB design ?Fall 2008http://www.cis.ksu.edu4CIS 764 Database Systems EngineeringPrevious (middleware model) -- ?? How related to DB design ? middleware model is object version replication of the data (not a static view, but dynamically linked)Fall 2008http://www.cis.ksu.edu5CIS 764 Database Systems EngineeringService oriented idea – * business method ( or data access) exposed as a web address * method still specified via assertions * coordination of methods described by business process modelFall 2008http://www.cis.ksu.edu6CIS 764 Database Systems EngineeringService oriented idea – ?? How related to DB ?Fall 2008http://www.cis.ksu.edu7CIS 764 Database Systems EngineeringService oriented idea – ?? How related to DB ? models distributed enterprise applications that use the DBFall 2008http://www.cis.ksu.edu8CIS 764 Database Systems Engineering Web Service: http://en.wikipedia.org/wiki/Web_service “software system with machine-2-machine interaction via network … ….common usage clients and servers communicate with http protocol “Fall 2008http://www.cis.ksu.edu9CIS 764 Database Systems EngineeringService Oriented Architecture http://en.wikipedia.org/wiki/Service-oriented_architecture systems structure … based on composition of web services system design framework … based on business process modeling … the linking and sequencing of service operations http://en.wikipedia.org/wiki/Business_process_modelingFall 2008http://www.cis.ksu.edu10CIS 764 Database Systems EngineeringService Oriented Architecture:How is it different than web-app (J2EE) architecture ?Fall 2008http://www.cis.ksu.edu11CIS 764 Database Systems Engineeringfoundation concepts …Fall 2008http://www.cis.ksu.edu12CIS 764 Database Systems Engineering Comparison of objects, components, web-services: R. Sessions, "Fuzzy Boundaries: Objects, Components, and Web Services", ACM Queue, Jan. 04 http://www.acmqueue.org/modules.php?name=Content&pa=showpage&pid=246 factors: location , environment, protocol: ◄ entity and the client in same process => objects ◄ different processes, same environment => component * (EJB, dotNet managed components ) ◄ different processes, different environments => service (web service, rpc ) --------------------------------- * restricted usageFall 2008http://www.cis.ksu.edu13CIS 764 Database Systems Engineering one issue is efficiency: object component serviceFall 2008http://www.cis.ksu.edu14CIS 764 Database Systems Engineering one issue is efficiency: “message passing” (calling) object << component << service Then why the focus, growth of web services?Fall 2008http://www.cis.ksu.edu15CIS 764 Database Systems Engineering one issue is efficiency: “message passing” (calling) object << component << service Then why the focus, growth of web services? more general level of reusable components, monolithic vs shared componentsFall 2008http://www.cis.ksu.edu16CIS 764 Database Systems Engineering Web service is access of object methods for remote use (by client or other “components” via web protocols.) Why web protocols? (vs rmi, rpc ?)Fall 2008http://www.cis.ksu.edu17CIS 764 Database Systems Engineering Web Service: http://en.wikipedia.org/wiki/Web_service structured / big “WS” …. XML, SOAP, WSDL, … “restful” … light weight … perhaps easier , not saferFall 2008http://www.cis.ksu.edu18CIS 764 Database Systems Engineering restful web service: “restful” … Representational State Transfer http://www.petefreitag.com/item/431.cfm e.g. Yahoo http://www.xfront.com/REST-Web-Services.html * stateless … each request must contain all info; not depend on object state * uniform interface … as http get, postFall 2008http://www.cis.ksu.edu19CIS 764 Database Systems Engineering "Web Services Protocol Stack" , Wikipedia http://en.wikipedia.org/wiki/Web_Services_Protocol_Stack http://en.wikipedia.org/wiki/SOAP http://en.wikipedia.org/wiki/Web_Services_Description_Language http://en.wikipedia.org/wiki/Universal_Description_Discovery_and_Integration http://en.wikipedia.org/wiki/Business_Process_Execution_LanguageService/transport layer …. Http, …Message encoding layer … XML: SOAP , RPCDescription protocol ……. XML: WSDLDiscovery service ……….. XML base, business services directoryBusiness process model … BPELFall 2008http://www.cis.ksu.edu20CIS 764 Database Systems Engineering http://www.w3schools.com/soap/soap_example.asp POST /InStock HTTP/1.1 Host: www.example.org Content-Type: application/soap+xml; charset=utf-8 Content-Length: nnn <?xml version="1.0"?> <soap:Envelope xmlns:soap=http://www.w3.org/2001/12/soap-envelope soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding"> <soap:Body xmlns:m="http://www.example.org/stock"> <m:GetStockPrice> <m:StockName>IBM</m:StockName> </m:GetStockPrice> </soap:Body> </soap:Envelope>Fall 2008http://www.cis.ksu.edu21CIS 764 Database Systems EngineeringResponse:HTTP/1.1 200 OK Content-Type: application/soap+xml; charset=utf-8 Content-Length: nnn <?xml version="1.0"?> <soap:Envelope xmlns:soap=http://www.w3.org/2001/12/soap-envelope soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding"> <soap:Body xmlns:m="http://www.example.org/stock"> <m:GetStockPriceResponse> <m:Price>34.5</m:Price> </m:GetStockPriceResponse> </soap:Body> </soap:Envelope>Fall 2008http://www.cis.ksu.edu22CIS 764 Database Systems Engineering Web
View Full Document
Unlocking...