In this report we shall attempt to discuss on of the emerging technology in the field of Information Technology which is Web Services. We will take into account the importance of web service, its basic framework and objective and also about the technological tools involved in the implementation and use of web services. This report also consists of a brief individual explanation of the components of web services such as XML, SOAP, WSDL, etc.
By an example from our day to day life, we know that different appliances work on different levels of electric current and voltage. Thus to work these different appliances we need adaptors for each appliance to be able to connect them to domestic electric current voltage. But many appliances mean as many adaptors, what if we were able to use just one adaptor for all different appliances; it will make our life so easy. Similarly Web Services serves as a common platform that standardizes the integration of all different computing systems and applications using the existing web infrastructure as a universal medium. The web Services enables machine to machine communication in form of data or messages irrespective of how diverse one application is from the other. Along with internal it also provides freedom for an application to interact beyond the corporate boundaries, thus enabling the system to converse directly with those of your suppliers, distributors and clients, i.e. Business-to-Business (B2B) integration which is necessary in these times of business dependencies but at the same time very difficult as you don’t have control beyond your own system. (Anne Thomas, 2003) Now that we understand Web services we will be able to actually put down its definition as- Technically the term Web Services can be describes as standardized way of integrating application-to-applications communication using the XML, SOAP, WSDL and UDDI open standards over an existing web infrastructure. XML tags the data, SOAP acts as data transfer channel, WSDL describes the available service and UDDI is a directory that lists all the available services for the users to search through. (www.webopedia.com, viewed 2008)
2.Web Services a comparison of technology
All middleware communication systems like CORBA, RMI or DCOM are based on the Distributed Computing Environment (DCE) of the Remote Procedure Call (RPC) style of middle ware that enables application-to-application communication but they have an inherent limitation that one RPC cannot communicate with another form of RPC system and should have similar RPC connection hook on both the machines. (www.wikipedia.org, viewed 12/05/2008) Thus the first biggest challenge we come across in using these RPC middleware is to find RPC software that supports all our programming languages and platforms involved at a single instance with feasible cost. This is where Web services come in because it uses XML format of message communication which is independent of all programming languages and platform. This makes it much more flexible and provides it the ability to talk to any system application be it all new programming or any old school programming language. The second issue in case of RPC middleware is that they have support from limited operating systems. Like in case of a Java platform, it only supports its RMI (Remote Method Invocation) and CORBA (Common Object Request Broker Architecture). Where as DCOM (Distributed Component Object Model) is only supported by Microsoft windows system. (Anne Thomas, 2003B) Here comes in Web Services again as they are loosely linked Communication systems and they make use of the pre existing network which is the WEB and as we know virtually all operating systems and...