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

BroaderB2B

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.

Easier Aggregation

Describe Services

Discover Services

IntegrateThemTogether

Provide a standards-based profile for all electronic services that are provided. Includes web sites, other electronic resources

Web ServiceVisibility

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. 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

4.

Service Types

1.

ImplementationsImplementers populate the registry withdescriptions of their businesses and the services they expose

2.

Large businesses apply the same architecture and technologies internally

5.

Software companies, standards bodies, and developers populate the registry with descriptions (specifications) of types of services

Public Registry Operation

IBM

HP (planned)

Microsoftother

other

• Peer registry nodes (websites)• Information registered

with any node• Registrations replicated

on a daily basis• Complete set of

“registered” recordsavailable at all nodes

• Common set ofSOAP APIs supportedby 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

UDDISOAP Response

UDDI RegistryNode

HTTPServer

SOAPProcessor

UDDIRegistry Service

B2B DirectoryCreate, View, Update, and Deleteregistrations Implementation-

neutral

GROUP DISCUSSION

19

WHAT

TO DO?