Research And Implementation On The Adaptation Of Heterogeneous Middleware Interoperability Based On Web Services Techniques

Nowadays, enterprise application system development in network environment has been greatly accelerated by the development and application of the middleware technology. Middleware platform masks the complexities of network environment such as openness characteristics, heterogeneousness in the low layer. It also provides a high level abstraction of the low layers in the network environment, and makes the development and deployment of application system easier. But unfortunately, different middleware vendors implement their high abstraction in different ways. Therefore, they have much difficulty in interoperating with different applications on different middleware platforms. Many applications on different middleware platforms come into being a variety of "Middleware Islands". It is an urgent problem, growing gradually, which lies on how to surpass these "Middleware Islands", that is to resolve the problem of interoperability of different middleware.In order to resolve this problem, this paper gives a middleware interoperability model first, and introduces a Web Services based heterogeneous middleware interoperation solution after analyzing and comparing with other methods. In this work, we define the publishing of an application on heterogeneous middleware to Web Services as Outbound Adaption, and define that implementation of an application on heterogeneous middleware accessing Web Services transparently as Inbound Adaption. This paper emphasizes on the research of Web Services/CORBA inbound adaption, we are doing the following research work:First, we analyz specifications and protocols related with Web Services/CORBA inbound adaption, and propose a model of gateway system based on virtual CORBA object, this model enables CORBA application to access Web Services transparently.Second, in order to satisfy the requirment of virtual CORBA object's creation and running in the model, we defined some term to describe status of gateway system, include: development time, deployment time, running time. Then we introduce operation of service deployment, service activation, and service management, all of them based on virtual CORBA object.Next, we discuss some problems about performance and scalability which gateway system may be faced, and bring forward some technical approaches to resolve these potential problem, these approaches include: service management technology based on DSI, service activate technology based on customized POA policy, data type model of scalability, two times scan technology based on symbol table and etc.Then, we explain some technical details about implementation of gateway system, including sub modules definitions, relationship of classes, algorithms of important methods, and so on.At last, we test the gateway system: the use of test case to verify correction of WSDL to IDL compiler in semantic and syntax, and the design of a simulation to test load performance of the gateway serve.The work and contribution of this paper have a definite rationale and realistic significance to the research and implementation of Web Services/CORBA inbound adaption, and have considerable referential values to related research.