The Design And Implementation Of Object Interceptor-mechanism Based On CORBA Specification

With extensive development of network distributed system, middleware technology is becoming more and more important. The technology of CORBA (Common Object Request Broker Architecture) made by OMG (Object management Group) is the most mature one, which becomes the mainstream standard of developing distributed object-oriented application in network environment. Today, CORBA technology is widely used in telecommunications, process automation, electronic commerce and other domains. It enables applications to call remote object just like local invocation, so we don't need to think about the location of remote object, implementation language, operation system platform, communication protocols and hardware platform. That makes developers not have to dwell on the details of the underlying network programming and reduces development difficulty. Customer requests information from Server. Server receives the request and returns the results to Customer by executing the concerned method of a remote object. Only make sure the information is correct can the communication process be safe, reliable and effective actually.With the expansion of application domains, demands for the quality of CORBA service are getting higher and higher. The distributed software must deal with many critical missions reliably. And interceptor-mechanism is the critical mechanism to provide high reliability. Interceptors are important components in CORBA specification. Using interceptors can inspect the information exchanged between Client applications and Server applications, know the process of ORB, intercept data stream in ORB process and implement various processing and control.In this paper, we are considering a new mechanism of interception based on CORBA technology, particularly based on CORBA interceptor specification. First of all, we analyze the background of this research subject and analyze the present research circumstances at home and abroad. Then we introduce some basic knowledge of CORBA and interception technology. And we design an interception model and extend the interceptor interfaces based on the study. At last we describe the functional design of sub-interceptor concretely, such as adding a new parameter to the request object to avoid sending repeatedly and abnormal information and adding a new filter part to the server context to ensure consistency of policy, status of performance and other things when send and receive messages. We also describe the designment and the workflow of sub-interception model, as well as the IDL for each interceptor interface, and implement sub-interception model finally.