10 Creating Object Models with UML
What Is UML?
Unified Modeling Language.
The Structure of a Class Diagram
Figure 10.1 A UML diagram of the Cabbie class.
Attributes and Methods
Attributes
all attributesshould be declared as private.
Methods
Including toomuch information (like parameters) in the class diagrams makes the object-modeldifficult to read. This is one of those issues that depends on your specifictastes.
AccessDesignations
In Java, thedefault type of access is protected. Protected access means that only classesin the package can access the attribute or method.? 說法有錯誤。
Inheritance
Multiple inheritance: Eiffel and C++
Interfaces
Composition
Aggregation
An aggregation is representedby a line with a diamond at the head.
Association
In UML notation,a plain line represents this service, with no shape on either end.
Note thatbecause there is no shape on either end of the line, there is no indication aboutwhich way the service flows. The figure shows only that there is an associationbetween the two classes.
Cardinality
Conclusion
You do not needUML to design OO systems, but UML is a tool that can be used to assist in thedevelopment of OO systems.