Java Reference
In-Depth Information
The sequence presented above is one of many possible sequences; in
addition, it is important to test abnormal conditions such as invalid codes for
employee, customer and product.
14.5
■
Prototype 2: Centralized system
In this prototype we develop a centralized version of the system running in
a single process. This system has a non-persistent database that resides in
memory.
14.5.1
Analysis
There are two main aspects of this prototype that should be considered: first
the behaviour of the system, second the information handled by the system.
The behaviour concerns the support of the operations of the employees at
the counter.
The information deals with three main entities: products, customers and
employees. They are related to each other as depicted in Figure 14.9.
Item
Item
code
name
quantity
price
Customer
code
name
1
item
1
customer
*
*
Transaction
acquisitions
Acquisition
code
timestamp
quantity
*
1
*
employee
1
Employee
code
name
password
Figure 14.9
Logical information class diagram
