Jerry Gao Ph.D.9/2001 The UML: Object-Oriented Modeling The Unified Modeling Language (UML) Instructor: Jerry Gao Ph.D. San Jose State University email:

Jerry Gao Ph.D. 9/2001

The UML: Object-Oriented Modeling

The Unified Modeling Language (UML)

Instructor: Jerry Gao Ph.D.

San Jose State Universityemail: [email protected]

URL: http://www.engr.sjsu.edu/gaojerry

Sept., 2001


Object-Oriented Modeling


Object-Oriented Modeling:- Focus on classes, objects and their relationships in the system- Represent the system using class diagrams and object diagrams- Is an iterative process

The major elements of the object-oriented modeling:- classes, objects and their relationships.

Purpose of object-oriented modeling:- to describe the system in terms of classes and objects- to provide a complete object-oriented view of the system - to help the understanding of the system through object-oriented analysis and modeling


A Class Diagram and An Object Diagram


1..*

Author

Name:Stringage: integer

Computer

Name:Stringmemory: integer

Uses0..1Class diagram

Bob:Author

Name:”Bob J.”age: 32

Bob’s Job PCComputer

Name:”Dell 466”memory: 64

Object diagram


Object-Oriented Modeling


How to perform object-oriented modeling?

- Step #1: Identify classes and objects in the system.- Find classes in the system- Identify their names and attributes- Identify their operations or functions

- Step #2: Find the relationships between classes- Find association relationships between classes- Find aggregation relationships between classes- Find inheritance (generalization) relationship between classes- Define the roles and cardinality of each class in the relationships.

- Step #3: Generate object diagrams based class diagrams


Finding Classes


Finding classes by asking the following questions:

- Do we have information that should be stored or analyzed?If so, check information-oriented classes. such as input/output

- Do we have external systems? If so, check the interface classes.

- Do we use any components, libraries? If so, check component-orientedclasses and library-oriented classes.

- Do we have any customers or users? If so, check user-oriented classes.

- Do we handle any devices? If so, check hardware-oriented interface classes.

- Do we have any business structure or organization involved in the system? If so, find organization-oriented classes.


Class Examples


Student

Name:Stringage: integerSS#: StringGPA: float

ReadStudent();UpdateStudent();CreateStudent();PrintStudent();

Figure

Size: Sizeposition: PositionType: FigureType

draw();setFiguer();scaleFigure();returnPosition();

operations

attributes


Association Relationship Between Classes


Student ComputerOwns

Student ComputerOwns

1..* 0..*

Multiplicity:

default one-to-one0..1 zero-to-one0..* or * zero-to-many1..* one-to-many


Roles in Association Relationship Between Classes


Person

married to

wife

husband

A husband is married to a wife. Both husband and wife are people.If a person is not married, then he or she cannot play the role of husband or wife, which means the married to association is not applicable.

Car Persondrives* *

company car driver

role

A person plays the role of a driver, and a car plays the role of a company car the relationship.


Aggregation Relationship Between Classes


Navy WarshipContains

Team Personmembers

* *

** Normal Aggregation

Shared Aggregation

A team is composed of team members. One person could be a member of many teams.


Aggregation Relationship Between Classes


Composition Aggregation

window

listbox

text

button

menu

*

*

*

*

contains


Generalization Relationship Between Classes


Normal Generalization -> Inheritance

Part-timeStudent

Student

Full-timeStudent

Part-timeStudent

Student

Full-timeStudent


A Class Diagram for Financial Trading


Customer Portfolio Trader

Instrument

Bond Stock Stock Option

1 Owns 1..* 1..* Handles 1

0..*

0..*

Con

tain

sC

onta

ins


Packages


Subsystem B

Subsystem A

Subsystem E

Subsystem C

Subsystem D

dependency


Packages


Subsystem B

Subsystem A

Subsystem D

Subsystem C

Subsystem E


The UML: Dynamic Modeling





Sept., 2001


Dynamic Modeling


Dynamic Modeling:- Focus on dynamic behaviors in the system- Use state, sequence, collaboration, and activity diagramsto present the behaviors of the system- Demonstrate how the objects interact dynamically

The results of dynamic modeling:

- State diagrams: -> describing object states and their changes in terms of events.

- Sequence diagrams:-> describing how objects interact and communicate with each other.

- Collaboration diagrams:-> describing how objects collaborate together by interactions

- Activity diagrams: -> another shows the object interactions for functionality and actors.


The Notation of State Diagram


State 1 State 2Event

State

starting point

State

end point

State Name

State Vars

Activities


A State Diagram for An Elevator


On first floor

Movingup

MovingDown Idle

Moving tofirst floor

Go up(floor)

Active at floor

Go up(floor)

Arrive at floor

Go down(floor)

Arrive at first floor

Time out


A State Diagram for An Elevator


On first floor

Moving up

do/moving to floor

Moving down

do/moving to floor

Idletimer = 0

do/increase timer

Moving tofirst floor

Go up(floor)Active at floor

Go up(floor)

Arrive at floor

Go down(floor)

Arrive at first floor

[Timer = time out] Guard-condition

Dynamic Modeling




Sept., 2001

Topic: The Unified Modeling Language


Sending Messages between State Diagrams

All Rights Reserved

Off On

On()

Off()

Play()Stop()

Off On/Stop

On()

Off()

Off()/Stop()

On/Play

Play()

Stop()

CD PlayerStop()Play()On() Off()

Remote control

Topic: The Unified Modeling Language

Jerry Gao Ph.D. 9/2001 All Rights Reserved

An And-Substates Example

Low Speed High Speed

Forward Backward

Running

concurrent substates

Sequence Diagram




Sept., 2001

Sequence Diagram

Sequence diagrams:- illustrate how objects interact with each other.- focus on interacting message sequences between objects

:ObjectNameSimple message

Synchronous message

[Guard-condition]

Return

Activation

lifeline

Sequence Diagram Example

:Computer

Print(ps-file)

Activation

lifeline

:PrinterServer :Printer

Print(ps-file)

Object[no queue]Print(ps-file)

Guard-condition

Synchronousmessage

Return

simplemessage

Sequence Diagram Example

:Computer

Print(file)

:PrinterServer :Printer

Print(file)

[printer free]Print(file)

:Queue

[printer busy]Store(file)

Documents

Jerry Gao Ph.D.9/2001 The UML: Object-Oriented Modeling The Unified Modeling Language (UML) Instructor: Jerry Gao Ph.D. San Jose State University email: