Information Technology Reference
In-Depth Information
1 . 5
C h a p t e r S t r u c t u r e
The chapter is structured as follows. Section
2
explains one of the main chal-
lenges faced by disconnected programming models, namely the need to support the
life-cycle of a generic disconnected application. Section
3
introduces two classes of
synchronization techniques: data replication and method replay. Section
4
discusses
two business application programming models. In one (Enterprise JavaBeans), the
programming model was intended for connected environments. In the other (Ser-
vice Data Objects), the programming model is intended to be used in both connected
and disconnected environments. We discuss interesting features of both program-
ming models, and show some of their implication with respect to building business
applications. We close, in Section
5
by evaluating various programming models for
disconnected applications.
1 . 6
M o t i v a t i n g A p p l i c a t i o n
The chapter will use the following “order entry” application to help motivate the
discussion.
Order Entry
enables agents to record customer orders using a stock cata-
log consisting of line-items and in-stock quantities. If a customer has not previously
placed orders, the agent enters information about the new customer into the system.
Figure 1
shows the top-level entities used in the application.
F
IG
. 1. Order entry sample application.
