Kingdom of Saudi Arabia Ministry of Higher Education Al-Imam Muhammad Ibn Saud Islamic University College of Computer and Information Sciences Introduction to Web Services Chapter 1

A bit of buzz (1) “By 2006, Web services will take hold as a competitive differentiator in business relationships and product innovation. Enterprises that want to remain competitive will need to use Web services to provide commonly requested data to their partners. It is imperative that enterprises develop a strategy for how to use Web services to develop products, including hard goods, digital goods and services.” Gartner Research, November 2003

Agenda Web Service definition. basic operational model of web services. tools and technologies enabling web services. benefits and challenges of using web services.

Distributed Computing Evolution

Four Paradigms of Computing Mainframe The era of “big iron” Client – Server (C/S) Networks and cheap desktop computing Internet Computing (n-tier architecture) Web moves to a computing platform Web services Web moves to a business platform

Distributed Computing Evolution Traditional C/S vs. Web Services

Distributed Computing Evolution Web Application vs. Web Services

Web Evolution A Web site is designed to be accessed by humans. A Web service is designed to be accessed by applications

Web Evolution Technology TCP/IPHTMLXML Purpose ConnectivityPresentationProgrammability Applications , FTP…Web PagesWeb Services Outcome Create the WebBrowse the WebProgram the Web

Today’s Web Web designed for application to human interactions Obtaining a variety of information. Shopping online. Reading headlines news This level of interaction is fine for many purposes. The current Web does not support software-oriented interactions very well. This is due to the limitations of HTML and the web server- based technologies, which focused on presentation and their inability to interact with another application.

Web services are changing everything The Web is everywhere. There is a lot more we can do! E-marketplaces. Open, automated B2B e-commerce. Business process integration on the Web. A more efficient method is needed that allows applications to interact directly with one another, automatically executing instructions. Web services improve Internet use by enabling program- to-program communication.

What is a Web Service? According to Gartner research “Web services are loosely coupled software components delivered over internet standard technologies.” Web services are self-describing and modular business applications that expose the business logic as services over the internet through programmable interfaces and using internet protocols for the purpose of providing ways to find, subscribe, and invoke those services.

Web Service definition Web services are typically implemented based on open standards and technologies specifically leveraging XML. The XML-based standards and technologies, such as Simple Object Access Protocol (SOAP); Universal Description, Discovery, and Integration (UDDI); Web Services Definition Language (WSDL); and Electronic Business XML (ebXML).

Figure 2.1 an example scenario of web services

The following is typical scenario The Travel service provider deploys its Web services by exposing the business applications obtained from different travel businesses like airlines, car-rental, credit card payment. The service provider registers its business services with descriptions. The registry stores the information about the services exposed by the service provider. The customer discovers the Web services using a search engine or by locating it directly from the registry and then invokes the Web services for performing travel reservations over the Internet using any platform or device.

Examples An e-commerce company can use a shipper’s web service to calculate the exact cost of a shipment. National weather forecasters use them to supply data to web-sites and news organizations. Stock prices are provided this way by major exchanges and corporations.