The fast track to Web services
The Internet is evolving from a static to a dynamic
communication and transaction medium. Originally conceived as purely a
presentation platform, it is fast becoming a network with a measure of
discriminating intelligence. This evolution is ushering in a new era
for the Internet, and with it a new breed of Web services based on
internationally accepted standards. Featuring a modular design, these
services may be mixed and matched at will. For enterprises, developers
and solution providers, this presents an excellent opportunity to
vault into new lines of business on a global scale.
But what exactly is a Web service? It is a service that every
client can access and use via Internet, whereby service transparency
is the operative term. Put simply, a Web service is comparable to a
black box. The client needs to know which functionality it is
receiving, and it must be able to use the functionality with some
measure of flexibility. The means and methods that the Web services
employs to provide that functionality are immaterial. What really
matters is that the service is delivered to the requesting end device
via a precisely defined interface. This is also a top priority for
developers when they want to combine different services to create an
entire application.
The notion of component-oriented, modular Web services is sure to
revolutionize how the Internet is used. The prevailing method of
distributing software in the form of all-in-one packages on media such
as CD-ROM or floppy disk is bound to lose currency.
Offering and using Web services: A crash course!
Though Web services may sound like music to the ears of companies,
users and developers, there is the matter of access and distribution
to consider: How do users obtain Web services, where can developers
peddle their modules?
To date this has required a healthy helping of perseverance and the
patience to engage in elaborate research. That is about change in the
not-so-distant future. Similar to hardcopy yellow pages, online
directories will list all information regarding Web services,
including descriptions of the given function, the developer, the
provider, and so on.
At least that is what Ariba, IBM, Microsoft, Software AG and
another 130 enterprises intend to bring about in a joint effort. The
ultimate goal of this UDDI
project is to bring to market Web services via publicly accessible
e-business directories. UDDI stands for Universal Discovery
Description and Integration.
XML: The Web-service enabler
Not surprisingly, the enabler of this development is once again
XML. Created on the basis of XML, UDDI defines further standards such
as Publishing and Discovery Services. These allow enterprises, users
and developers to publish information about themselves, their products
and their services, and search through entries for specific providers
or potential partners.
At the heart of the UDDI architecture is a business registry with
three components - white, yellow and green pages. All salient
information - names, addresses, industries and lines of business,
product ranges, contact options and Web service offerings - are listed
in these directories. UDDI uses the aptly named Web Service
Description Language (WSDL), a derivative of XML, to describe Web
services.
As a standard for online databases, UDDI is destined for greatness
- the number and standing of project members speaks volumes about its
chances for success. But perhaps more important, UDDI defines the
structure of online directories on the basis of XML. XML is already a
global industry standard, and nothing will stay its advance. And that
is not just an opinion held by people with a vested interest in XML,
it is the general consensus in the industry.
Two giants, two approaches
In future many functions will be accessible over the Web in the
form of individual and independent components. That is precisely what
Web services are all about. At present two rival enterprises are
pursuing different strategies to implement access to Web services via
Internet - Microsoft with its .NET strategy and Sun with the Open
Network Environment (ONE). In principle, the objectives of these two
strategies are very similar.
The idea is for new intelligent services to provide as much
information as possible to users via a more dynamic and more personal
Internet environment. Microsoft and Sun are both wagering that
individual modules for personalizing services and delivering
information is the way to go. Users are automatically authenticated
via a unique profile, and then the desired offers are made available
via Internet, including an appointment book, mail, fax, instant
messaging, stock exchange quotations, and sports results, to mention
just a few.
Sun and Microsoft rely on XML as the standard language for
cross-platform data exchange. All news, information and data are
available everywhere, at any time regardless of access appliance, be
it a computer or any other end device. Although the visions of Sun and
Microsoft with regard to future Internet use are virtually identical -
the mantra for both companies is any place, any time, any device - in
technical terms there are marked differences in the way they are
approaching this goal. Microsoft's .NET strategy relies on a
three-layer model: A universal runtime engine controls and manages the
execution of individual threads, a library provides uniform APIs
(Application Programming Interfaces) for programming applications, and
Active Server Pages+ (ASP+) display dynamic Web pages whose contents
are generated on the serve side.
The focus of Microsoft's .NET strategy is obviously on Microsoft
products like the Windows operating systems and products of the .NET
Server family. Sun has charted an altogether different course. The
company geared its ONE strategy to be as open as possible.
Consequently, its focus is less on specific IT environments and
operating systems. Sun's own programming language Java serves as the
underpinning, and all services are implemented on Java basis. Uniform
interfaces for applications and data are created in combination with
expansions such as JDBC and NetBeans. To deliver information to end
devices, Sun has opted for the XML, HTML and WML standards.
For developers, the Sun strategy means more openness, and therefore
a wider range of choices in terms of platform support. The reason for
this is that Sun ONE allows the use of other programming languages to
address virtually every operating system platform, provided of course
that programmers use the libraries for the given language.
Web services spoken here
Regardless of the preferred implementation strategy - Sun ONE or
Microsoft .NET - Web services pose a formidable challenge for
developers. However, they also present a huge window of opportunity.
Courtesy of XML, Web services may be developed and linked on both
platforms, ONE or .NET. Both strategies enable operating system
functionality to be transferred to the Web. Developers are empowered
to create new applications that integrate all functions of the
Internet and may be deployed independently irrespective of
device.
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