In this exercise, you create the Transfer Money Participants diagram. The Transfer Money Participants diagram models the static structure of the Transfer Money use case.
The Transfer Money Participants diagram shows the classes that participate in the Transfer Money use case. You model the participants, along with their relationships, to describe the domain of the system. In addition to entities, and boundary classes, the Transfer Money Participants diagram contains the TransferMoneyControl control class. Control classes represent the implementation of business rules or logic. A control class represents a self-contained process that interacts with boundary classes. Boundary classes are used to abstract the control classes from entities.
Modeling is an iterative process. You can add, remove, or modify participants at any time as you better understand the details of the system that you are modeling. In this tutorial, you create the basic outline of the Transfer Money participants diagram. You add the remaining details of the diagram when you create the Transfer Money sequence diagram in the next exercise.
You create the Transfer Money participants diagram in the Account Operations package.
You have started the Transfer Money Participants diagram by reusing the classes that you created in the Display Balance use case realization. Many of the same classes are used in more than one functional area. You created the Account, Transfer, and MenuForm classes in the Display Balance use case realization.
The TransferMoneyControl participant is a control class that represents the business logic of the Transfer Money functional area.
The TransferMoneySummaryForm participant is a boundary class that represents the summary form that is displayed when the Transfer Money transaction has completed.
The TransferMoneyForm participant is a boundary class that represents the money transfer form that is displayed when the user clicks Transfer Money on the main menu.
Because the TransferMoneyControl participant is a control class, it is central to and depends on most of the other classes in the use case. In this exercise, you create the TransferMoneyControl class relationships.
The MenuForm and TransferMoneyForm boundary classes depend on the TransferMoneyControl class.
You have created the basic outline of the Transfer Money participants diagram. Your diagram should look similar to the following figure:
To continue, proceed to Exercise 2.8: Creating the Transfer Money sequence diagram.