TRAVEL RESERVATION SYSTEM USING WEB SERVICES COMPOSITION LANGUAGE

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TRAVEL RESERVATION SYSTEM USING WEB SERVICES
COMPOSITION LANGUAGE

• Pratik K Kadakia
• Adviser Dr. Haiping Xu
• CIS Department, UMass Dartmouth

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Web Service Roles
Service Registry
Find
Publish
Service Consumer
Service Provider
Communicate
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The Functions of the Travel Reservation System

• Search for Flights by entering source and
  destination cities.
• Search for Hotels by entering city name.
• Search for rent-a-car companies.
• Allow users to book flight, hotel as well as car.

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Architecture for the Travel Reservation System
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Software Tools

• Java Server Pages (JSP used as the front end)
• J2SE v1.5.0_06 SDK (used as a development
  environment)
• Mysql 4.0.21-win. (used as the back end database)
• Java Web Services Developer Pack v 1.6 ( used for
  developing and deploying web services)(jwsdp-1.6)
• Tomcat Server tomat50-jwsdp (used as the server
  and also serves as a container for jwsdp-1.6 )

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Home Page of Travel Application
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Snapshot - 1

• After login, user can select one of the web
  services.

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Snapshot - 2

• The WSDL (Web Service Definition Language) of the
  hotel web service.

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Snapshot - 3

• Web services result is returned to the travel
  agent.

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Travel Reservation System using Web Service
Composition Language

• Web Services Composition
• Is the task of combining and linking existing
• Web services to create new Web processes.
• It adds value to the collection of services, by
  combining them according to the requirements of
  the problem.

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Advantages of using Web Services Composition
Language

• The logic for composition of web services is
  modularized and is separated from the rest of the
  application.
• This logic can be re-used by different
  applications.
• Any changes to the business logic can be directly
  made in the module without varying the other
  parts of the application.

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Examples of Web Service Composition Languages

• BPEL
• BPEL is an XML language that supports process
  oriented service composition. Developed by BEA,
  IBM, Microsoft, SAP, and Siebel.
• Semantic Web (OWL-S)
• The Web Ontology Language for Services OWL-S
  (previously known as DAML-S) is a ontology that
  enables automatic service discovery, invocation,
  composition, interoperation, and execution
  monitoring.

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Business Process Execution Language for Web
Services (BPEL4WS)

• It stands for Business Process Execution Language
  for Web Services.
• It provides a language for the formal
  specification of business processes and business
  interaction protocols.
• It enables efficient integration of existing Web
  Services.

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Some Terminologies in BPEL4WS

• In BPEL, participating services are called
  partners.
• Message exchange or intermediate result
  transformation is called an activity.
• The composition result is called a process.
• A process consists of a set of activities.

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How to Define a Process

• To define a process, we use
• a BPEL source file (.bpel), which describes
  activities
• a process interface (.wsdl), which enables a
  process to interact partner services.
• an optional deployment descriptor (.xml), which
  contains the partner services physical locations

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ActiveBPEL 2.0

• The ActiveBPEL engine is an Open Source
  implementation of a BPEL engine.
• It reads BPEL process definitions (and other
  inputs such as WSDL files) and creates BPEL
  processes.
• The ActiveBPEL engine runs in any standard
  servlet container such as Tomcat.

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Introduction to ActiveBPEL 2.0

• There are three main areas in the architecture of
  the ActiveBPEL engine the engine, processes, and
  activities.
• The ActiveBPEL engine coordinates the execution
  of one or more BPEL processes.
• Processes are in turn made up of activities,
  which may in turn contain or link to further
  activities.
• The ActiveBPEL engine creates a process from a
  BPEL process definition (an XML file) and then
  executes this process

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A Snapshot of the ActiveBPEL

• The Active BPEL engine requires an installed and
  properly configured servlet container like
  tomcat.

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Architecture for the Travel Reservation System
Using BPEL4WS
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An Example

• BPEL Pseudo Code
• If (Hotel provides shuttle service to
• airport)
• Then
• Invoke Car Services with criteria to sort
• results according to cost.
• Else
• Invoke Car Service with criteria to sort
• results according to nearest to airport

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Conclusions

• Our approach offers value-added integrated
  services by combining existing web services.
• It supports reuse and extension of existing
  services.
• It is scalable in terms of increasing number of
  online services.

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Future Work

• Show the feasibility of this approach using more
  complicated case studies.
• Model web services composition using formal
  languages such as Petri nets to support formal
  verification.
• Use agent technique to automate the web services
  composition process.

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References

• http//java.sun.com/webservices/docs/1.6/tutorial/
  doc/index.html
• http//www.activebpel.org/
• Current Solutions for Web Service Composition, by
  Nikola Milanovic and Miroslaw Malek Humboldt
  University, Berlin
• http//www.zurich.ibm.com/pdf/ebizz/icaps-ws.pdf

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Thank You

• QUESTIONS?