WEB SERVICES: THE NEW WAVE OF WEB TECHNOLOGY

1
WEB SERVICES THE NEW WAVE OF WEB TECHNOLOGY

• Wafa Khorsheed, Eastern Michigan University
• Asad Khailany, Eastern Michigan University

2
Outline

• Introduction
• Definition Of Web Services
• Web Services Architecture
• Web Service Operations
• Example Application Of Web Services
• WSDL Partial definition of GetCatalog Service
• Benefits Of Web Services

3
Introduction

• Business organizations have embraced the Internet
  and Web Technology as soon as they discovered the
  create value of the Web for conducting business.
• The Internet presented incredible value and reach
  for businesses of all sizes.
• Great efficiencies, cost reduction and new
  business opportunities have led the way for
  organization to use this technology.
• This type of technology is commonly referred to
  as service-centric computing. Service-centric
  application require the integration of many
  collaborating applications on the Internet to
  achieve a business functionality

4
Definition Of Web Services

• self-contained, self-describing, modular
  applications that can be published, located, and
  invoked across the Web.
• Web Services is any program that is callable by
  another program across the web in a
  platform/language/object model independent
  manner, using standard web protocols (XML, SOAP,
  WSDL, UDDI, etc.)
• There are three main uses of Web services.
• Application integration
• Business integration
• Commercial Web services

5
Web Services Architecture

• Service providers Provide services, and maintain
  a registry that makes those services available.
• Service requestors Work with service brokers to
  discover Web services, then invoke those services
  to create applications.
• Service brokers they are the clearinghouses for
  services. Service brokers act as matchmakers
  between service providers and service requestors.
  The services broker is referred to as UDDI
  (Universal Discovery, Description and
  Integration).

6
Web Service Operations

• Publish/Unpublish Publishing and unpublishing
  involves advertising services to a registry
  (publishing) or removing those entries
  (unpublishing). The service provider contacts the
  service broker to publish or unpublish a service.
• Find The find operation is performed by service
  requestors and service brokers together. The
  service requestors describe the kinds of services
  they're looking for, and the service brokers
  deliver the results that best match the request.
• Bind The bind operation takes place between the
  service requestor and the service provider. The
  two parties negotiate as appropriate so the
  requestor can access and invoke services of the
  provider.

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Web Services Architecture
8
Example Application Purchase Order
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WSDL Partial definition of GetCatalog Service

• ltbinding name"PartOrderingServiceBinding"
• type"GetCatalogServiceType"gt
• ltsoapbinding style"rpc" transport"http//sche
  mas.xmlsoap.org/soap/http"/gt
• ltoperation name"GetCatalog"gt
• ltsoapoperation soapAction"http//www.PartOrd
  ering.com/GetCatalog"/gt
• ltinputgt
• ltsoapbody type"InMessageRequest"
• namespace"urnPartOrdering"
• encoding"http//schemas.xmlsoap.
  org/soap/encoding/"/gt
• lt/inputgt
• ltoutputgt
• ltsoapbody type"OutMessageResponse"
• encoding"http//schemas.xmlsoap.
  org/soap/encoding/"/gt
• lt/outputgt
• lt/operationgt
• lt/bindinggt

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Benefits Of Web Services

• Promote interoperability
• Enable just-in-time integration
• Reduce complexity through encapsulation.
• Give new life to legacy applications