Introduction
With the WWW market growing, system integrators are also faced with the issue of how to huild stable, scalable systems out of these disparate technologies (particularly in systems that span hetero geneous platforms). This survey anounces the two dominate integrating Objects, CORBA and COM and relations between the emerging visual tools JavaBeans in Java and two integration domains.
What are JavaBeans, CORBA and COM?
JavaBeans is a portable, platform-independent component-based visual programming written in Java. It enables developers to write reusable components once and run them anywhere - benefiting from the platform-independent power of Java. JavaBeans acts as a Bridge between proprietary component models and provides a seamless and powerful means for developers to build components that run in ActiveX container applications.
The Common Object Request Broker Architecture(CORBA) is the Object Management Group's standard for distributed objects to allow applications to communicate with one another no matter where they are located or who has designed them. The Object Request Broker(ORB) is the middleware that establishes the client-server relationships between objects.
The Component Object Model(COM) is Microsoft's framework fro developing and supporting program component objects. Is is aimed at providing similar capabilities to those defined in CORBA, the framework for the interoperation of distributed objects in a network. Whereas OLE provides services for the compound document that users see on their display, COM provides the underlying services of interface negotiation, life cycle management(determining when an object can be removed from a system), licensing, and event services.
Interoperation
Sun provides the JavaBeans Bridge for ActiveX. The Bridge provide users of legacy OLE/COM/ActiveX containers with the ability to embed and use portable JavaBeans components in the same way they would previously embed and user platform-specific OLE/COM/ActiveX components.
JavaBeans works with any network model, including CORBA, DCOM, etc. JavaBeans integrates well with CORBA IDL, which is an excellent solution for customers in a heterogeneous distrubuted computing environment with platform independent components. However, RMI for Java is recommended by Sun to Java inter-object communication.
CORBA and COM are the two leading technologies for enabling application integration. Although both of them are object-oriented, they have different origins. COM begins on the disktop, framing application integration in terms of the document and other graphical components. CORBA began at the network, viewing application integration as a messaging layer wichi successfully routes messages among application components acroos a network.
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