Java Reference
In-Depth Information
Control module
B/L
C/P
Client
Server
P/P
Figure 19.1
The system architecture
Prototype 2: Asynchronous communication
. The interaction between
client and server is asynchronous. The server notifies the client of
relevant events.
■
Prototype 3: Web communication
. The library of components implements
the mechanisms that allow client and server to interoperate using sockets.
The client side of the test application is an applet or a servlet that
supports remote access to the server from a web browser.
■
19.4
■
Prototype 1: Synchronous communication
The focus of this prototype is on the multi-task execution model and on the
synchronous and deferred-synchronous communication models. Remote
control modules communicate via Java RMI.
19.4.1
Analysis
The central component of the MMI framework is the autonomous control
module that executes multiple tasks concurrently, coordinates access to
shared resources, and allows remote clients to exploit its services through
the internet.
Similar requirements were analysed in previous case studies. In par-
ticular, Prototype 3 of Chapter 15 (Geographical information system) deals
with multi-clients' remote access to a shared collection of thematic data-
bases, while Prototype 2 of Chapter 13 (Supervisory control and data acqui-
sition system) exemplifies the use of Java RMI for the interconnection of
remote control modules. Chapter 10 (Mobile robot exploration) and
Chapter 11 (Car parking) present two different execution models.
