1. Web Services
Pushpendra Paliwal

2. History
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Structured programming
Object-oriented programming
Distributed computing
Electronic data interchange
World Wide Web
Web services

3. Who Was First?
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What company first proposed the web
services concept?
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Hewlett-Packard's e-Speak in 1999
was an enabler for e-services
Microsoft introduced the name "web
services" in June 2000
MS "bet the company" on its web services
strategy
now every major vendor is a player

4. What is Web Service?

5. Class Interface & Webservice

6. Service-Oriented Science
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Idea: need standards and interfaces to
encapsulate information tools as services
No knowledge of inner workings required
Service oriented architecture: systems as
networks of loosely-coupled, communicating
services
Service oriented science: scientific research
enabled by networks of interoperating
services

7. Web Service Challenge
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Describe operations service supports
Define protocol to invoke services over
Internet
Operate server to process incoming
requests

8. Web Service Challenge
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Interoperability
Scale
Management
Quality Control
Incentives

9. SOAP and REST
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REST (Representational State Transfer)
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Architecture style of networked systems
JAX-WS
SOAP (Simple Object Access Protocol)
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Standard for sending messages between
applications
JAX-RS

10. SOAP and REST

11. SOAP and REST

12. SOAP VS REST
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RESTs sweet spot is when you are exposing
a public API over the internet to handle
CRUD operations on data. REST is focused
on accessing named resources through a
single consistent interface.SOAP –
messaging protocol for transporting
information and instructions between
applications (uses XML)

13. SOAP VS REST
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SOAP brings it’s own protocol and focuses on
exposing pieces of application logic (not data)
as services. SOAP exposes operations.
SOAP is focused on accessing named
operations, each implement some business
logic through different interfaces.

14. Why SOAP ?
WS-Security
 WS-Atomic Transaction
 WS-Reliable Messaging
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15. Why SOAP ?
WS-Security
 WS-AtomicTransaction
 WS-ReliableMessaging
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16. Open, Standard Technologies
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XML – tagging data such that it can be
exchanged between applications and
platforms
SOAP – messaging protocol for
transporting information and
instructions between applications (uses
XML)

17. Open, Standard Technologies
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WSDL – a standard method of
describing web services and their
specific capabilities (XML)
UDDI – defines XML-based rules for
building directories in which companies
advertise themselves and their web
services

18. SOAP

19. The Big Picture
UDDI Registry
Registry refers client to WSDL document
WSDL
Document
Client queries registry to locate service
Client accesses WSDL document
Web service returns SOAP-message response
Client sends SOAP-message request
WSDL provides data to interact with web service
Client
Web Service Code

20. UDDI
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UDDI defines an XML-based format that
describes electronic capabilities and business
processes
Entries are stored in a UDDI registry
UDDI Business Registry (UBR)
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"white pages" – contact info, description
"yellow pages" – classification info, details
"green pages" – technical data
uddi.microsoft.com

21. SOAP
WSDL
Class
SEI

22. WSDL
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Web services are self-describing
Description is written in WSDL, an XMLbased language through which a web
service conveys to applications the
methods that the service provides and
how those methods are accessed
WSDL is meant to be read by
applications (not humans)

23. WSDL-Simplified
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It is similar to interface
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Name
Input
Output

24. WSDL
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http://www.webservicex.net/ws/WSDetails.
aspx?WSID=64&CATID=12

26. Real Web Services
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Accenture
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Live Information Models
stock traders access real-time information
from a single terminal
Dollar Rent-a-Car + Southwest Airlines
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Southwest runs Unix
Dollar runs MS Windows
Dollar turned its system into a web service

27. More Examples
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Web service broker sites
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www.xmethods.net
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www.salcentral.com

28. Online Resources
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www.deitel.com
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www.w3.org
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web services, C#
World Wide Web Consortium (W3C)
recommendations, news, mission, FAQs
www.w3.org/History.html
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history of computing and internet from
1945 to now

29. Online Resources
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www.webservices.org
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news, standards, vendors, platforms,
products, applications, case studies,
security mechanisms
www.webservicesarchitect.com
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online journal for web service developers;
tools, vendors, business models, additional
resources

30. Online Resources
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www.ws-i.org
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web service interoperability organization
(WS-I); promote interoperability among
services created in different languages and
platforms; white papers, news, FAQs

31. Online Resources
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www.xml.com/lpt/a/2002/02/06/
webservices.html
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"Web Service Pitfalls": limitations,
unresolved security issues
www.webservices.org/print.php?
sid=201
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"Web Services—A Reality Check":
transactions, security, QoS

32. More Info
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www.w3.org/2002/ws
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www.uddi.org
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explanation; business benefits
www.oasis-open.org
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web services activity
technical work and standards
www.ebxml.org
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technology and business benefits