class_diagramsJAVA类的编写··.ppt

CIT16A JAVA 2 Class Diagrams - in UML 2 UML 2 The UML is a standardized, graphical notation for specifying, visualising, constructing and documenting a software system. In UML 2 there are two basic categories of diagrams: structure diagrams and behaviour diagrams. Every UML diagram belongs to one these two diagram categories. The purpose of structure diagrams is to show the static structure of the system being modelled. They include the class diagrams. THE BASICS Person ssn: int lastName: String firstName: String middleName: String +setLastName(aLastName:String): void +getSsn(): int +getLastName():String The UML representation of a class is a rectangle containing three compartments THE BASICS Class attribute list The attribute section of a class (the middle compartment) lists each of the classs attributes on a separate line. The attribute section is optional, but when used it contains each attribute of the class displayed in a list format. The line uses the following format: name : attribute type Class operations list The classs operations are documented in the third (lowest) compartment of the class diagrams rectangle. Like the attributes, the operations of a class are displayed in a list format, with each operation on its own line. Operations are documented using the following notation: name(parameter list) : type of value returned VISIBILITY There is a notation of visibility for attributes and operations. UML identifies four types of visibility: public, protected, private and package. You place the visibility mark in front of the attributes or operations name, and package. Notation Visibility Type + Public - Private # Protected ~ Package RELATIONSHIPS IN CLASS DIAGRAMS Relationships between classes in a class diagram are denoted by lines with special endpoints. There are several different kind of relationships, such as: Generalisation Association Dependency RELATIONSHIP TYPES IN A CLASS DIAGRAM Generalisation (is – a relationship) Inheritance – Points fro