|
Conclusion
WSDL
- WSDL
stands for Web Services
Description Language.
WSDL is a document written in XML. The document describes a Web
service. It specifies the location of the service and the operations
(or methods) the service exposes. WSDL is a suggestion by Ariba,
IBM and Microsoft for describing services for the W3C
XML Activity on XML Protocols.
W3C Publishes Working Drafts
for Web Services Description Language (WSDL) 1.2. The World Wide
Web Consortium (W3C) has announced
the publication of initial working draft specifications for Web
Services Description Language (WSDL) Version 1.2 and Web Services
Description Language (WSDL) Version 1.2: Bindings. WSDL is "an
XML format for describing network services as a set of endpoints
operating on messages containing either document-oriented or procedure-oriented
information. Work in progress at W3C
indicates that WSDL might become a W3C Working Draft before the
end of 2002, and an official Recommendation before the end of year
2003.
Further
Readings:
1.
W3C Specification draft on
WSDL
2. W3School
introductory tutorial
3. Zvon
Reference on WSDL
4. MicroSoft
Specification Page
WSDL
is accepted and supported by IBM, Microsoft, Macromedia and Ariba.
How
do they work?
Let
us discuss a bit on how web services are working. Web services can
be created using any platforms for example, MS .NET or Sun ONE.
Now it has to be registered in a UDDI service registry. While registering,
the services should have the metadata about the service, that is,
the necessary information about the service, explaining how to access
and integrate the service. This metadata will be written in XML.
This web service can be accessed by other web services who are also
already registered in some UDDI registered,using SOAP,WSDL and XML.
Here SOAP is used to access the components and WSDL to make the
necessary bindings and to describe the service as a set of Ports.
The ports helps the service for input and output the messages, that
is for necessary interactions. Lets summarize the operations in
a nutshell.
Creation:
1. Create a web service
2. Describe the service with WSDL (XML)
3. Register the service in a UDDI repository/Registry.
Accessing and using:
1. A service is located
by another service or user, by searching UDDI registries.
2. Using SOAP the service gets the functions of the located service.
3. Interactions between the requested service and the requester
service started.
Which
tools to use?
If you are a Microsoft
developer already into web applications development you can learn
.NET development tools. Java developers are in need to move into
Sun ONE(Open Network Environment)/J2EE. But regardless of the tools
and tchnology base you use to develop the web services, everyone
should study and understand XML and XML based family of technologies.
Conclusion
Now you may ask " Where can we apply
web services?" . A few examples now are like Stock price information
gathering, whether reports, Flight reservations etc., As the technology
explores many things are possible through web. Right now we have
only tools and standards which are still not matured. Its yet to
be simplified,and till then we have to work only with the technologies
which are yet to improve a lot. But its needless to say that its
time to learn and practice some web services development for any
compant which is in web related development and its good if its
now.
References
and Related Links:
wsindex.org
Do you have a web service with
you?Add here!
Practical
web services examples
Learn how to create web services
with this online examples
IBM
at web services(R1)
Learn from IBM, Lots of news and articles
Searchwebservices
Contains white papers and other
online links
Coldrooster.com
A Sample web service from Coldrooster
|
