Web Services Part 1 -- Qinwei Zhu Part 2 – Yongqun He

What Are Web Services? Web services are a new breed of Web application. They are self-contained, self-describing, modular applications that can be published, located, and invoked across the Web.

Generic Web Service Architecture

Why we use Web Services? The Web provides a uniform and widely accessible interface and access glue over services. Web service providers can use the Internet to market their services to a potentially huge set of possible clients. For clients, it can mean quicker and more flexible application development.(all the wording)

Examples of Web Services Microsoft Passport: a convenient authentication service used in Hotmail A credit checking service that returns credit information when given a person's social security number. A stock quote service that returns the stock price associated with a specified ticker symbol.

Web Services Platform = XML + HTTP Or = XML + HTTP + SOAP + WSDL + UDDL Or = XML + HTTP + SOAP + WSDL + UDDL +XAML + XLANG + XFS +……

SOAP Simple Object Access Protocol – is a protocol specification that defines a uniform way of passing XML-encoded data SOAP envelop SOAP header SOAP body

POST /StockQuote HTTP/1.1 Host: Content-Type: text/xml; charset="utf-8" Content-Length: nnnn SOAPAction: "Some-URI" <SOAP-ENV:Envelope xmlns:SOAP-ENV= SOAP-ENV:encodingStyle=" DIS

HTTP/ OK Content-Type: text/xml; charset="utf-8" Content-Length: nnnn <SOAP-ENV:Envelope xmlns:SOAP- ENV=" SOAP- ENV:encodingStyle=" ng/"/> 34.5

UDDI Universal Description, Discovery and Integration – provides a mechanism for clients to dynamicaly find other web services

UDDI  White pages: Information such as the name, address, telephone number, and other contact information of a given business.  Yellow pages: Information that categorizes businesses. This is based on existing(non- electronic) standards.  Green pages: Technical information about the Web services provided by a given business.

UDDI schema

Registry APIs (SOAP Messages) Inquiry API –Find things find_business find_service find_binding find_tModel –Get Details about things get_businessDetail get_serviceDetail get_bindingDetail get_tModelDetail Publishers API –Save things save_business save_service save_binding save_tModel –Delete things delete_business delete_service delete_binding delete_tModel –security… get_authToken discard_authToken

e.g.1 Books% e.g.2 (?) ( and return result……) "2AB346C B0-756B-0003CC35CC1D“

StockQuote Service WSDL description of a standard stock quote service interface WSDL source document. <keyedReference tModelKey="uuid:C1ACF26D D70- 39B756E62AB4" keyName="uddi-org:types" keyValue="wsdlSpec"/>

WSDL Web Services Description Language Service – a collection of ports Port – a single endpoint defined as a combination of a binding and a network address Binding – a concrete protocol and data format specification for particular port type Port type – an abstract set of operations supported by one or more endpoints Operation – an abstraction description of an action And so on…

WSDL  There are tools available to read a WSDL file and generate the code required to communicate with an XML web service  Apache AXIS: generating Java stubs/skeletons given a WSDL file  Microsoft Visual Studio.NET

References ndex.html ndex.html ibm.com/developerworks/webservices/ ibm.com/developerworks/webservices/