|
Identifier |
000378529 |
Title |
HWSC - A Tool for Web Services Composition |
Alternative Title |
HWSC - Εργαλείο Σύνθεσης Ηλεκτρονικών Υπηρεσιών |
Author
|
Τζαγκαράκης, Χαράλαμπος Εμμανουήλ
|
Thesis advisor
|
Πλεξουσάκης, Δημήτρης
Νικολάου, Χρήστος
Μαγκούτης, Κώστας
|
Abstract |
Web services can be used in a variety of applications, ranging from
household tools to video games, assisting users in solving different types of
problems. However, the most significant impact is witnessed in businesses
that use Web services for commercial and integrated business solutions.
A Web service is typically characterized by two sets of parameters: a
set of inputs (usually represented by a SOAP request) and a set of outputs
(usually represented by a SOAP response). A successful execution of a Web
service with all required input parameters (which are assumed to be available)
is expected to produce the required output parameters. Given a request
containing a set of input parameters and requesting a set of output
parameters, a typical problem is to find candidate single Web services that
can produce the required output if the required input is provided. This problem
is defined as Web Service discovery in literature.
In this thesis we focus on the case where there is not any single Web
service that fully satisfies a given request. In this case we must compose
multiple Web services in order to satisfy the given request. Web Service
composition aims to address that problem. Web Service composition involves
combining and coordinating a set of services in a workflow with the purpose of
achieving functionality that cannot be realized with any individual service.
Several service composition models have been proposed, with the most
prominent ones being service orchestration and service choreography.
We present a tool named HWSC which reads a request expressed by
a use in a predefined format and attempts to answer the request by creating a
composite service combining Web services from a repository. The tool first
reads the WSDL descriptions of the Web Services contained in the repository
and then applies a composition algorithm that results in a composite service
that satisfies the request. The innovative characteristics of the tool are: 1)
Provides a lightweight approach to composition based only on WSDL inputoutput
descriptions. 2) Uses similarity techniques while reading a user request
allowing for a 20% probability of error in input and output names. 3) Uses an
algorithm based on STRIPS, an automated planner in artificial intelligence, in
order to find the composition sequence that satisfies the user request. 4)
Exports the final composition sequence in a BPEL template file, which can be
edited by tools supporting BPEL and executed by a BPEL engine.
|
Language |
English |
Subject |
Web Services |
|
Web Services Composition |
|
Ηλεκτρονικές Υπηρεσίες |
|
Σύνθεση Ηλεκτρονικών Υπηρεσιών |
Issue date |
2012 |
Collection
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School/Department--School of Sciences and Engineering--Department of Computer Science--Post-graduate theses
|
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Type of Work--Post-graduate theses
|
Views |
521 |