Unified Modeling Language (UML) Class Diagram & Sequence...

Class DiagramSequence Diagram

Unified Modeling Language (UML)Class Diagram & Sequence Diagram

Miaoqing HuangUniversity of Arkansas

Spring 2011

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Outline

1 Class Diagram

2 Sequence Diagram

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Outline

1 Class Diagram

2 Sequence Diagram

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Class Diagram

Class diagrams show the static structure of the classes thatmake up a system or subsystemUse case diagrams show the functional requirements of a system(or subsystem) from the perspective of the end-user of a system

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Classes

Classes are shown as rectanglesClass nameOther compartments

AttributesOperationsOther predefined compartments

Name conventionClass’ name

Have no space between multiple wordsCapitalize the first letter in eachsubsequent world

Name of features in compartmentsHave no space between multiple wordsCapitalize the first letter in eachsubsequent world except the first world

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Associations among classesAssociations represent relationships between(instances of) classes

Classes collaborate with each other by passingmessages and receiving responses

Association nameIndicates the nature of the associationAssociate name should begin with a capital letterNavigability: use arrow to indicate how to interpretthe association

Unidirectional associationBidirectional association: without arrow

Role nameIndicate the role played by a class in anassociationAttached to the corresponding association endCan use the same rule of naming features to namethe role, i.e., low case the very first letter andcapitalize the first letter of subsequent word

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Multiplicity

Multiplicity indicates how many objects may participate in thegiven relationship (during the run-time of your software system)

*: 0..infinity1: 1..1n..m: low_bound..up_bound

Multiplicity of an association end is not shownThe multiplicity is not knownThe multiplicity is not specified

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Aggregation

Aggregation symbol.Assembly consists of components.Component is part of an assembly

Aggregation associationAn instance of one class may consist of instances of another classwhole-part association

whole is made up of parts

Use a solid line with an unfilled diamond shape at the endDiamond is connected to the class that is the aggregate

A part is capable of existing outside of whole-part association8 / 23


Composition

Document

SectionFrontMatter Index1 0..1

0..11..*

1..*

Document

FrontMatter [1]

Section [1..*]

Index [0..1]0..1

1..*

Composition associationwhole-part association

The life-cycle of the ‘part’ cannot extend beyond the life-cycle of the‘whole’

Two different notationsFilled diamond notationGraphical containment

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Generalization

Generalization relationship is(sometimes) described as being a kindof relationship

Generalized class: superclass(supertype)Specialization: subclass (subtype)

Generalization allows the inheritance ofthe attributes and operations of asuperclass by its subclasses

Subclass can override the operations inthe superclass

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More on attribute and operation

Attribute and Operation Typesfeature-name : type

Attribute and Operation Visibilityprivate (-)

The feature is available only within the class that owns the featurepublic (+)

The feature is available to any class associated with the class thatowns the feature

protected (#)The feature is available within the class that owns that feature andany subtype of that class

package (∼)The feature is available only to other classes in the same package

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Outline

1 Class Diagram

2 Sequence Diagram

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Purpose of Sequence Diagram

Static diagramUse case diagrams show the static relationship between actorsand use casesClass diagrams show the static relationship between classes orinstances

A program is a sequence of interactions among objects (i.e.,instances of classes)

Difficult to understand a program only with static diagramsPurpose of sequence diagram

Model the high-level interactions between active objects in asystemModel the high-level interactions between subsystems

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Sequence Diagram Example

:Journeyfirst:CarSharer

:SharingAgreement

:RecordAgreementControl

:RecordAgreementUI

CarMatchAdministrator

new agreementdetails set create sharing

agreement

get car sharer ID

find by ID

get journey ID

find by ID

add journey set sharingagreement

set first arranged

loop [i=1..no of car sharers]

sd Create new agreement

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NotationFrame


:SharingAgreement


:RecordAgreementUI



agreement

get car sharer ID

find by ID

get journey ID

find by ID


set first arranged



Sequence diagrams aredrawn in frames

New in UML 2.0

Time runs verticallyLifelines are arrangedhorizontally

Represent object instances

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NotationFrame


:SharingAgreement


:RecordAgreementUI



agreement

get car sharer ID

find by ID

get journey ID

find by ID


set first arranged



Sequence diagrams aredrawn in frames

New in UML 2.0

Time runs verticallyLifelines are arrangedhorizontally

Represent object instances

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NotationLifeline

Participating instances are represented bylifelines

Dashed vertical lineRectangle representing an object

Syntax Explanationo An object named oo : C An object named o of class C:C An anonymous object of class C

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NotationMessages and Activation box

A message is shown using an arrow going from the sender to thereceiver

Different types of messagesSynchronous

The sender waits until the reply is receivedAsynchronous

The sender does not wait for the reply; instead, it carries on the nextstep in its own sequence

CreationA message causes the creation of an object instance to which themessage is sent

Reply

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NotationMessages and Activation box

A message is shown using an arrow going from the sender to thereceiverDifferent types of messages

SynchronousThe sender waits until the reply is received

AsynchronousThe sender does not wait for the reply; instead, it carries on the nextstep in its own sequence

CreationA message causes the creation of an object instance to which themessage is sent

Reply

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Sequence Diagram Example with Explicit Reply


:SharingAgreement


:RecordAgreementUI



agreement

get car sharer ID

find by ID

get journey ID

find by ID


set first arranged



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NotationCombined Fragments

A sequence of messages can be combined into a fragmentLoop, branches, ...


:SharingAgreement


:RecordAgreementUI



agreement

get car sharer ID

find by ID

get journey ID

find by ID


set first arranged



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NotationCombined Fragments

:ReliableDistributor:Order

dispatch

loop [ for each item ]

:NormalDistributor

dispatch

alt [ value > $10,000 ]

[ else ]

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Exercise

Lay out the lifelines for instances of the classes Student, EnrollInSeminar,SecurityLogon, StudentDatabase, and Seminar. Add the followingmessages to the diagram. Note, keep the order of the messages.

1 Request to enroll to seminar A2 Create an instance of SecurityLogon class3 Provide name4 Provide student number5 Provide password6 Verify the student (name, number, password)7 Return verification result8 Return the student information9 Add the student into the seminar A10 Confirmation of enrollment of seminar A11 Display the confirmation to student

Note: EnrollInSeminar class is both the main control and the main interfacewith the student

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Unified Modeling Language (UML) Class Diagram & Sequence...

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