Build Distributed Component Based On Web Services

Web services are a new breed of Web application. They are self-contained, self-describing, modular applications that can be published, located, and invoked across the Web. Web services perform functions that can be anything from simple requests to complicated business processes. Once a Web service is deployed, other applications (and other Web services) can discover and invoke the deployed service. The advent of Web services is revolutionizing enterprise application communication, expanding applications' reach and making it much easier for disparate applications to communicate with one anotherObserver design pattern define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically. In this paper, we apply Observer design pattern to web services, service provider acts as subject and serve ice requester acts as observer, In order to make use of this design pattern in web services system, we only need to change method of Observer into web service method. With the property of Observer, we get an asynchronous web service system, and we can combine a few web services into a web service component with one or a few function, inside which each web service depend on others. This component can be used in an application or be extended to a more complicated component. This architecture for Web services is called the Distributed Asynchronous Web Services Component (DAWSC). DAWSC for Web services benefits from the decoupled nature of Web services and the asynchronous nature of the Observer pattern. In this paper, we will detail the principle of this kind of component and detail how to realize this architecture in .NET framework and at the end of the paper, we give an example of DAWSC and a web service application using DAWSC.