Web Services - Information

8/11/2019 Web Services - Information

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Web Services


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History Structured programming

Object-oriented programming

Distributed computing

Electronic data interchange

World Wide Web Web services


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Who Was First? What company first proposed the web

services concept? Hewlett-Packard's e-Speak in 1999 was an enabler for e-services

Microsoft introduced the name "webservices" in June 2000

MS "bet the company" on its web servicesstrategy

now every major vendor is a player


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Open, Standard Technologies XML tagging data such that it can be

exchanged between applications and

platforms

SOAP messaging protocol fortransporting information and

instructions between applications (usesXML)


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Open, Standard Technologies WSDL a standard method of

describing web services and their

specific capabilities (XML)

UDDI defines XML-based rules forbuilding directories in which companies

advertise themselves and their webservices


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Advantages Open, text-based standards

Modular approach

Inexpensive to implement (relatively)

Reduce the cost of enterpriseapplication integration

Incremental implementation


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Real Web Services UC-Berkeley

Unified Communications Technical Project

unify email, voice, and fax into in-boxesaccessible from cell phones, PDAs, or e-mail clients

Eastman Chemical Company distributors access chemical catalog in real-

time and push info to customers


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Real Web ServicesAccenture

Live Information Models

stock traders access real-time informationfrom a single terminal

Dollar Rent-a-Car + Southwest Airlines

Southwest runs Unix Dollar runs MS Windows

Dollar turned its system into a web service


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More Examples Web service broker sites

www.xmethods.net

www.salcentral.com
http://www.xmethods.net/http://www.salcentral.com/http://www.salcentral.com/http://www.xmethods.net/


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Online Resources www.deitel.com

web services, C#

www.w3.org World Wide Web Consortium (W3C)

recommendations, news, mission, FAQs

www.w3.org/History.html history of computing and internet from

1945 to now
http://www.deitel.com/http://www.w3.org/http://www.w3.org/History.htmlhttp://www.w3.org/History.htmlhttp://www.w3.org/http://www.deitel.com/


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Online Resources www.webservices.org

news, standards, vendors, platforms,

products, applications, case studies,security mechanisms

www.webservicesarchitect.com

online journal for web service developers;tools, vendors, business models, additionalresources
http://www.webservices.org/http://www.webservicesarchitect.com/http://www.webservicesarchitect.com/http://www.webservices.org/


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Online Resources www.ws-i.org

web service interoperability organization

(WS-I); promote interoperability amongservices created in different languages andplatforms; white papers, news, FAQs
http://www.ws-i.org/http://www.ws-i.org/http://www.ws-i.org/http://www.ws-i.org/


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Online Resources www.xml.com/lpt/a/2002/02/06/

webservices.html

"Web Service Pitfalls": limitations,unresolved security issues

www.webservices.org/print.php?

sid=201 "Web ServicesA Reality Check":

transactions, security, QoS
http://www.xml.com/lpt/a/2002/02/06/http://www.webservices.org/print.php?sid=2-1http://www.webservices.org/print.php?sid=2-1http://www.webservices.org/print.php?sid=2-1http://www.webservices.org/print.php?sid=2-1http://www.xml.com/lpt/a/2002/02/06/


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The Big Picture

Client

UDDI RegistryWSDL

Document

Web Service Code

Client queries registry to locate service

Registry refers client to WSDL document

Client accesses WSDL document

WSDL provides data to interact with web service

Client sends SOAP-message requestWeb service returns SOAP-message response


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XML Developed from Standard Generalized

Markup Method (SGML)

XML widely supported by W3C Essential characteristic is the separation

of content from presentation

XML describes only dataAny application that understands XML

can exchange data


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XML

XML parser checks syntax

If syntax is good the document is well-

formed XML document can optionally reference

a Document Type Definition (DTD),also

called a Schema If an XML document adheres to the

structure of the schema it is valid


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SOAP

SOAP enables between distributedsystems

SOAP message has three parts envelopewraps entire message and

contains header and body

headeroptional element with additionalinfo such as security or routing

bodyapplication-specific data beingcommuicated


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WSDL

Web services are self-describing

Description is written in WSDL, an XML-

based language through which a webservice conveys to applications themethods that the service provides andhow those methods are accessed

WSDL is meant to be read byapplications (not humans)


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UDDI

UDDI defines an XML-based format thatdescribes electronic capabilities and businessprocesses

Entries are stored in a UDDI registry

UDDI Business Registry (UBR) "white pages" contact info, description

"yellow pages"

classification info, details "green pages" technical data

uddi.microsoft.com


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OASIS

Not competition to W3C

Ensure that businesses acquire e-

business tools that meet their needs

United Nations Centre for TradeFacilitation and Electronic Business

produced Electronic Business XML(ebXML)


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More Info

www.w3.org/2002/ws web services activity

www.uddi.org explanation; business benefits

www.oasis-open.org

technical work and standards www.ebxml.org

technology and business benefits
http://www.w3.org/2002/wshttp://www.uddi.org/http://www.oasis-open.org/http://www.ebxml.org/http://www.ebxml.org/http://www.oasis-open.org/http://www.oasis-open.org/http://www.oasis-open.org/http://www.uddi.org/http://www.w3.org/2002/ws


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SOAP

WS-Security

WS-Policy WS-Trust WS-Privacy

WS-SecureConversation WS-Federation WS-Authorization

Web Services SecurityArchitecture


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SOAP

WS-Security



WS-Security

Describes how to attach signature and encryption headers toSOAP messages; how to attach security tokens such as X.509certificates and Kerberos tickets


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WS-Policy

SOAP

WS-Security



Describes the capabilities and constraints of the securityand business policies on intermediaries and endpoints


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WS-Trust

SOAP

WS-Security



Framework for trust models that enables web services tointeroperate securely.


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WS-Privacy

SOAP

WS-Security



Model for how web services and requesters state privacypreferences and organizational privacy practice statements


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WS-SecureConversation

SOAP

WS-Security



Manage and authenticate message exchanges between parties,including security context exchange and establishing and derivingsession keys


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WS-Federation

SOAP

WS-Security



Manage and broker trust relationships in a heterogeneousfederated environment, including support for federated identities.


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WS-Authorization

SOAP

WS-Security



Manage authorization data and authorization policy.

Documents

Web Services - Information