Web Services

Web Service: Simple definition : “ Service Offered On the Web “ Technically : “ A Web Service is a programmable application component that is accessible through standard web protocols”.

Introduction to Web Services It’s a business to business application.  Traditional business to consumer model  An enterprise puts up its inventory on the web.  The consumer uses an internet connection and a browser to browse interrelated links & makes a transaction.

Business to Business Model An enterprise utilizes data and other resources of another enterprise. Inherent Problems:  Isolation Of Business Process within Incompatible Systems  Changing Business Scene  Accelerated Pace of Change

SOAP A light weight protocol with a simple architecture. Utilizes Http as the transport. It can be used with a combination of other protocols. It can cross firewalls.

Web Service Working Client Initiates a Request. The Web Service Provider Receives the Request. Service Provider Checks for the Type of Service Requested. Provider Re-directs the Request to an Application Provider.

The Application Provider Receives and Process the Request and Sends It Back to the Service Provider. The service provider redirects the result to the Client.

Web Service WSDLSOAPUDDI Web Services Framework

UDDI Universal description,discovery & integration. Basically a database consisting of all the application providers. Termed as the “yellow pages “ of the web services.

UDDI Structure : White pages Yellow Pages Green Pages. Name & Contact Business Service categorization Service Oriented Technical data.

WSDL Web Services Description Language.

WSDL.. Defines a Relationship Between the UDDI & Web Service Provider. Description in the form of a XML document. Provides the technical aspects of the service.

Web Service

Role Of XML 1. Ideal mechanism to transfer short structured message between peer applications. 2. Can be easily customized for existing systems. 3. New Encryption techniques not needed. 4. Ease due to the presence of SOAP.

Technology Providers 1. Microsoft’s.Net Service. 2. Sun’s Java web development integrated with apache modules.

Problems :  Security Constraints  Quality Unchecked.  Problems with distributed computing like data mapping & transactional integrity.

Conclusion: Web Services offer an immense potential for software development by integrating various vendors across different platforms. With sufficient security features implemented Web services can speedup a transaction among a distributed & decentralized environment.