Web Service - Made IT simpleby Reji K Paul (Software Programmer, Excellone Technologies)
E-business is made simple by web services. These
services, using different software standard protocols are helping
businesses create sophisticated web applications that integrate
many features and content without platform hassles, at a considerably
lesser cost. The fact that companies don't have to renew their infrastructures
for accessing it; makes it more popular nowadays.
To quote IBM Web Services are self contained,
self describing modular applications that can be published, located
and invoked across the web. Web services perform functions which
can be anything from simple requests to complicated business processes.
The current breed of Web applications, takes your
business to more constant access to customers, consumers, and vendors
around the globe. Services on the web serve the best and fastest
for booking agencies for travel, dining, theaters, cabs etc.
There are diverse varieties of web applications,
with a self-describing nature. For the users who are in need of
web applications it can cater to them while linking with other related
web applications. In the end, the users will be served what they
need without knowing that they are being served by different web applications from different locations.
The Standards and Tools the participants
Web services need minimal human intervention, thus
the software standards are quite high. SOAP, UDDI & WSDL, the new
connecting software standards side by side with matured software
standards like XML and HTTP web services; can be created and complemented
to interact with other web services dynamically.
1. XML- A worldwide-agreed software standard
and Extensible Mark Up Language; XML is the backbone of the web
service. XML is moulded to describe data and unlike HTML, XML tags
are not predefined. DTD, Document Type Definition, used to formally
elaborate self-describing, XML standard was put forward in 1996
by a team headed by Jon Bosak. The World Wide Web Consortium (W3C)
has also recommended, XML which is derived from Structured Generalized
Markup Language (SGML) parent and Hyper Text Markup Language (HTML).
2. UDDI The UDDI (Universal Description,
Discovery & Integration) project based on existing Internet standards;
is a yellow page type directory of all businesses that render services
on the web.
- The UDDI has an independent platform with a neutral implementation.
- In the opinion of industry analysis like Gartner Group, Forestar
Research and Seybold. The UDDI will be the core initiative for
accelerating B2B adoption in future.
- UDDI defines the ways and means for discovering Services on
the web.
3. SOAP - SIMPLE OBJECT ACCESS PROTOCOL.
SOAP is an XML-based object invocation protocol, which is made to
transfer structured and typed information on the Web.
- This is simple and high weight protocol specification for invoking
methods on web server, services, components and objects.
- SOAP primarily made for distributed web applications to interact
over HTTP and through corporate firewalls have non-defined the
usage of HTTP & XML to access service, objects and service in
a platform independent manner.
4. WSDL
- Web Services Description Language: The documents written in
XML describe a Web service by specifying the location and operation.
- The World Wide Web Consortium (W3C) has announced the publication
of initial working draft specifications for Web Services Description
Language (WSDL) version 1.2 & WSDL version 1.2 Bindings.
Tools in use
To quote IBM, WSTK (Web Services Tool Kit) is a
software development kit that includes demos and examples to aid
in designing and executing web service application that can automatically
find one another and collaborate in business transactions without
additional programming or human intervention.
- Visual Studio. Net: The comprehensive tool set for rapidly building
and integrating XML web services, based on Microsoft windows
application and Web solutions.
- Java Web services Developers Pack: JAVA WSDP is an integrated
tool set which in conjunction with the java platform allows Java
developers to build, test and deploy XML web applications and
services.
- JAVA XML pack, Java Server Pages Standard Tag Library (JSTL)
Java WSDP Registry Server, Web Applications Deployment Tool, Ant
Build Tool and Apache Tomcat container are the web technologies
included in Java WSDP.
The way it works
Basically 3 steps are involved in making a service
on the web.
i) Creation of service on the
web using any platform like MS, .Net or Sun ONE.
ii) Describing the service with WSDL (XML) i.e. metadata or necessary
information about accessing and integrating the service should be
written.
iii) Register the service in a UDDI registry / repository.
To access & use
- By searching UDDI registries to locate a service by another
service / user.
- Using SOAP can access the functions of the located service.
- The interaction between the requester service and requested
service starts.
Being aware of what service on the web is and how
it (a web service) works; one also needs to be knowledgeable about
the risks involved, as when the customers are not paying for the
software technology - mere integration cannot boost the sales. So
one needs to have the market for commercial web services in the
needy areas.
Ultimately, you are the one to make a 'choice',
because the assistance you choose will decide your future. They
are to provide it with technical as well as business consultancy
along Implementation Consulting and Assistance, which can cover
almost all the aspects of risk.
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