Client Server Architecture - Programming GPS and OpenStreetMap Applications with Java - page 143

Chapter 11

Client Server Architecture

11.1 Introduction

With a good understanding and technical specification of the RealObject
client, we consider the server side. The server has to be able to identify,
authorize, and handle a large number of clients in an ordered manner.
The server design has to be open to the inheritance of simple objects to
higher-level constructs with additional attributes and methods.
Similar to the extension of the RealObject , the RealObjectServer should
implement the technical prerequisites for every real-object application. The
software design should restrict the ROApp to a lean semantic layer running
on the server.

11.2 Status Report

At this point, the reader should have a notion of real objects, real-object
applications, and object-oriented methodologies. Large portions of the Java
Tutorial Trails have been used in the roaf.book packages. These packages
can be deleted now when the actual project sources are moved to the roaf
root folder.
The roaf.gps and roafx.gui packages are shown in Figures 4.1 and 5.1
(pages 52 and 60) and look similar to the roaf.book packages. The new
roaf project will contain the finalized ROAF library roaf with a sample
ROApp in roa.ldn .
A library is part of the JVM concept. Only with an installed Java Class
Library can higher-level programming tools (like the String class) be used
on any JVM. Java provides means to install packages as a library so that
the packages do not have to be defined in a class path and become part of
the JVM.
Every JVM participating in the framework should run with the roaf
packages to provide a common basis for the real-object application frame-
work. Although this has not been enforced in any way yet, it should be
kept in mind for long-term development. The Java reflection technology

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