WEB SERVICE DESCRIPTION LANGUAGE (WSDL)

Introduction  WSDL is an XML language that contains information about the interface semantics and ‘administrivia’ of a call to a Web Service  Once you develop a Web Service you publish its description and a link to it in a UDDI repository so that potential users can find it  When someone wants to use your service, they request the WSDL file in order to find out the location of the service, the function calls and how to access them  Then they use this information in your WSDL file to form a SOAP request to the computer

Definitions  Definitions: - WSDL is an XML-based language used to define Web Services and describe how to access them. - WSLD is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information.

Working of WSDL Figure 1. A client invoking a Web service.

Working of WSDL contd. Figure 2. WSDL terminology used for describing Web services.

Working of WSDL (with Java) contd.

Where does it fit in?

What is UDDI?  Universal Description Discovery and Integration  Industry-wide initiative supporting web services  Specifications  Schemas for service description  Schemas for business (service implementers) description  Developed on industry standards (XML, HTTP, TCP/IP, SOAP)  Applies equally to XML and non-XML web services  Implementation  Public web service registry and development resources

Industry-Wide Project Support  All major technology providers  Global corporations  Strong resource and product commitment  Roadmap for transition to standards body  Unprecedented collaboration  XML and Web Services recognized as core standards  Competition on services built on a common model  Technology, platform, and development language neutral

What Problems Do We Solve? An organization needs to create 400 electronic relationships with partners, each with its own standards and protocols Broader B2B A small business wants to be “plugged in” to every marketplace in the world, but doesn’t know how SmarterSearch A B2B marketplace cannot get catalog data for relevant suppliers in its industry, along with connections to shippers, insurers, etc. EasierAggregation Describe Services Discover Services Integrate Them Together Provide a standards-based profile for all electronic services that are provided. Includes web sites, other electronic resources Web Service Visibility Publish for Accessibility

Foundation for Web Services Ubiquitous Communications: Internet Universal Data Format:XML Service Interactions:SOAP Formal Service Descriptions:WSDL Broad Industry Support, Simple Process Publish and Discover Services:UDDI

UDDI Registry Entries  Standards Bodies, Agencies, Programmers, Publishers register specifications for their Service Types  Service providers register precise information about themselves and their Web services

Business name General business description –Any number of languages Contact info –Names, phone numbers, fax numbers, web sites, etc. Known identifiers –List of unique identifiers for a business D-U-N-S, Thomas, domain name, stock ticker symbol, other

Business categories –3 base taxonomies in V1 Industry: NAICS (Industry codes - US Govt.) Product/Services: UNSPSC (ECCMA) Location: Geographical taxonomy (ISO 3166) …easy extension in upcoming releases

New set of information businesses use to describe how to “do e- commerce” with them –Nested model Business process (functional) Service specifications (technical) Binding information (implementation) –Programming/platform/ implementation agnostic –Services can also be categorized

How UDDI Works UDDI Registry 3.3. UDDI Registry assigns a programmatically unique identifier to each service and registration Marketplaces, search engines, and business applications query the registry to discover services at other companies and to facilitate integration Service Types Implementations Implementers populate the registry with descriptions of their businesses and the services they expose Large businesses apply the same architecture and technologies internally Software companies, standards bodies, and developers populate the registry with descriptions (specifications) of types of services

Public Registry Operation IBM HP (planned) Microsoft other Peer registry nodes (websites) Information registered with any node Registrations replicated on a daily basis Complete set of “registered” records available at all nodes Common set of SOAP APIs supported by all nodes Compliance enforced by business contract All technologies applied Interoperability verified constantly UDDI.org queries Applications Marketplaces End Users Developers

UDDI and SOAP User UDDI SOAP Request UDDI SOAP Response UDDI Registry Node HTTP Server SOAP Processor UDDI Registry Service B2B Directory Create, View, Update, and Delete registrations Implementation- neutral

GROUP DISCUSSION 19 WHAT TO DO?WHAT TO DO?