Web Service

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Web Service

• Jianguo Lu

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Service Oriented Architecture
publish
find
interact
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A concrete SOA
UDDI Registry
Points to description
WSDL
publish
Finds Service
Describes Service
Web Service Provider
Service Consumer
SOAP
Communicates with XML Messages
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Web service definitions

• A web service is an application accessible to
  other applications over the internet
• Self-contained, modular business applications
  that have open, internet-oriented, standard based
  interfacesUDDI Consortium
• a software application identified by a URI,
  whose interfaces and bindings are capable of
  being defined, described, and discovered as XML
  artifacts. A web service supports direct
  interactions with other software agents using
  XML-based messages exchanged via Internet-based
  protocols. --W3C
• a standardized way of integrating Web-based
  applications using the XML, SOAP, WSDL, and UDDI
  open standards over an Internet protocol
  backbone. XML is used to tag the data, SOAP is
  used to transfer the data, WSDL is used for
  describing the service available, and UDDI is
  used for listing what services are
  available--Webopedia

More concrete
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Web Service definition

• encapsulated, loosely coupled, contracted
  software objects offered via standard protocols
  --ZapThink Research
• Encapsulated
• Web Service implementation is invisible to
  entities outside the service
• Exposes an interface but hides details
• Loosely Coupled
• Service and consumer software can be redesigned
  independently

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Why Web Service

• Just as the web revolutionized how users talk to
  applications, XML transforms way applications
  talk to each otherBill Gates
• Web services will be bigger than Java or XML.
  Rod Smith, VP of Emerging Technology, IBM
• Web services are expected to revolutionize our
  life in much the same way as the internet has
  during the past decade or so.Gartner
• By 2004, 40 of the financial services
  transactions and 35 of online government
  services will be web service-based. Gartner
• There are web services for Google, Amazon, Fedex,
  EBay
• It is another hype?