Chapter 6

Instructors' Guide

Ch 1 Ch 2 Ch 3 Ch 4 Ch 5 Ch 6 Ch 7 Ch 8 Ch 9 Ch 10 Ch 11 Ch 12
  1. The major characteristic of a component is that it is a unit of independent deployment. In contrast, an object is simply a unit of instantiation. There may be many objects in a component. In addition, components must satisfy much stricter requirements than objects. For example, components may not have persistent state, which transcends the boundaries of a transaction. See slide component-definition.
  2. See slide technology-matrix.
  3. These are all, in some way, standards for interoperability. There is an obvious commonality since they all use some form of an Interface Definition Language. There are, however, many differences. For example, Microsoft (D)COM is being enforced as a de facto standard for the Windows platform, whereas both CORBA and the ODMG standard are developed by a consortium to arrive at a vendor-independent standard, encompassing multiple platforms. See section Interoperability.
  4. A number of perspectives relevant to the evaluation of the Java platform are mentioned in slide Perspectives, among which are the software engineering and system development perspectives. In brief, the Java platform is very promising as it provides numerous APIs. There may be some doubt, however, about its efficiency. Also, questions have been raised about issues such as the maintainability of Java code.
  5. See section Workgroup.
  6. One of the problems that occurs is how to integrate the (remote) object types with the types provided by the library. In section Crush the notion of client adaptors has been introduced as a solution to this problem.

slide: Answers