(Post 07/07/2006) In the year 2000, Microsoft
introduced the term Web Services which was a major component of .NET Technology.
As the name suggests, Web Servicescan be thought of as a service available
on the Web which can be used across by different applications to make
use of the service.
Figure 1 |
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Introduction to Web Services
In today s Business, information exchange and efficient
communication is the need of the day with respect to IT. In today s world
the whole IT revolves around WEB, where Web services play an important
role in distributed computing through WEB to connect computers in different
remote locations.
In the year 2000, Microsoft introduced the term WEB SERVICES
which was a major component of .NET Technology. As the name suggests,
WEB SERVICES can be thought of as a service available on the Web which
can be used across by different applications to make use of the service.
For example, in a tourism application, instead of creating a separate
sub module/application for reservation process, the reservation module
can be made available as a web service and that service can be reused
by the tourism application, which makes the application simple.
There are a variety of Web service solutions offered
by different vendors. The different vendors who have offered web services
in the market are
.Net Web Service
With respect to web service, .net Platform of Microsoft
is one of the most complete environments for building, deploying and accessing
web services. The development environment has support for multiple programming
languages and contains tools for reusing code.
Web service is a software service that is
- Exposed on the Web for being used by different computers connected
in the network
- Using HTTP and it uses XML to describe data.
- Using SOAP as a transport vehicle to transmit between the different
computer systems
Java Web Service
The Sun one s Java 2 platform has good support for web
service. Java is portable and has support for XML and standard networking
technologies which makes it ideal for building internet applications based
on web service.
The Web services use XML to transfer data between other
applications on different computers using Internet protocols. They operate
on any network to achieve special tasks that other applications can invoke
and use.
Architecture of Web Service: (Figure
1)
The architecture of Web service involves three distinct
components
- Service Provider
- Service Requestor
- Service Broker
The job of the Service provider is to provide access
across the web for a particular service of business system. For providing
the access the provider creates a service and publishes the service in
the service registry on the service broker.
The job of the Service requestor is to bind the service
offered by the service provider. Before binding the service initially
the requestor searches the service in the registry and locates the service
in the registry.
The service broker is used as a repository of the service
description.
Characteristics of Web Service
Web Services available in a centralized remote location
can be accessed through web so that the applications can make use of the
web service and access the methods of the web service.
Web service has a service interface. This service interface
is usually a XML document that helps in web service being called by another
program.
Web service can interact with any other web service.
For interacting with other web services, the basic requirement is a network
that supports HTTP protocol and for hosting and accessing the web service,
XML is used.
Web services are supported by loosely coupled applications.
They can be broken into any number of logical service components and each
of these components can be physically distributed among any number of
computers with the support of HTTP transfer and XML, which makes the application
to be distributed for fast retrieval and storage
While using the web services in a remote location, the
systems should be on the web and the services needs to be registered with
service registry for reference.
Advantages of Web service:
- Cross Business Integration:
- Since the communication is service-to-service communication
in the process of interaction in business, there exists an integration
of related business. And any architecture that supports XML can
take part in this cross Business Integratioin.
- Improved Efficiency:
- Since the total process is broken into smaller efficient application
service components the need of the system also is broken down
into smaller units which makes it easy to deploy and troubleshoot
the application.
- Closer Customer relationships :-
- Since the application is available in the web as a service the
organisation can conduct customer surveys to understand the needs
of the customer and improve the relationship of the organisation
and the customer.
- Reduced Complexity :-
- The complexity of the application is reduced with the help of
encapsulation Here with respect to web services there is no need
that the end user has any pre knowledge with respect to the architecture
of the Web services that is being offered. The user interacts
with the interface of the components
Disadvantage of Web service:
It is compulsory that XML support is required as the
whole Web services revolve around HTTP and XML. Cost of deploying will
be high as only limited technologies are used in offering the Web service.
In case of new technologies being introduced to provide the services,
the cost of deploying will reduce. Service management duplicated in many
components.
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