lecture07

Computer Engineering Department

Computer Engineering Department

Object Oriented Software Modeling and Design

CE 350Abdel-Karim Al-Tamimi, Ph.D.

[email protected]://faculty.yu.edu.jo/

altamimi

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mailto:[email protected]

Overview

• Interaction Diagrams:– Sequence Diagram– Collaboration Diagram

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Interaction Diagrams

• Scenario modeling describes how the objects in a system interact with each other in a scenario

• A scenario is a sequence of events that occurs during one particular execution path within a use case of a system

• Each event involves the interaction of objects passing messages between them

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Interaction Diagrams• An interaction diagram can be used to model the

collaborating objects in scenarios, showing the – objects involved in the scenario and – the messages sent and received by them

• These objects may be external or internal to the system

• The messages represent the invocation of operations of the receiving objects

• Two kinds of interaction diagrams: sequence diagrams and collaboration diagrams

• Sequence diagrams focus on the time sequencing of messages

• Collaboration diagrams focus on the structural organization of the links between collaborating objects

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Interaction in UML

• Interaction diagram: models the behavior of a group of objects that work together to achieve a user goal

• An interaction describes a series of messages that a selected set of participants exchange within a situation limited in time

• The entire diagram represents one interaction, but can be using several messages

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Sequence Diagram

• Sequence diagrams emphasize the sequence in which messages are exchanged

• A sequence diagram helps us identify a set of collaborating objects involved in a scenario of a use case

• A sequence diagram has two dimensions: the vertical dimension and the horizontal dimension

• Object icons are placed horizontally at the top of the sequence diagram, and messages are passed between them

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Sequence Diagram: Example

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Sequence Diagram: Example

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Naming Format Notation

An object of an unspecified class.

A named object of a specified class.

An unnamed object of a specified class.

Interaction Diagrams Notation in UML

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Interaction Diagrams Notations in UML

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Object Category

Description Graphical Notations

Actor Object An external entity that interacts with the system

Entity Object

An object that models the data in the system. It often represents an object in the problem domain

Interaction Diagrams Notations in UML


Object Category

Description Graphical Notations

Boundary Object

An object that handles the communication between actor objects and the system.

Control Object

An object that models the flow of control and functionality that do not naturally belong to entity objects or boundary objects.

UML Notations - Messages


Message Description Notation

Procedure call or other nested flow of control

The message sender waits for the completion of the procedure call of the message receiver (waits for a reply)

Asynchronous communication

The sender dispatches a message and immediately continues with the next step of execution (there are no reply arrows)




Return message

Message returned from the procedure call

Message with travel delay

The message will take a significant amount of time to arrive at the receiving object. (This is only used in sequence diagrams.)




Lost Message The sender is known, the receiver is not

Found Message

The sender is unknown, and the receiver is known

Create Message A message creates a new instance

Messages Notations Summary


Sequence Diagram: Lifeline and Activation


Object withLifeline

Object withActivation

Activation: show the duration of the execution of a method inresponse to a message

Sequence Diagram: Branching


ConditionalMessage

Transmission

Sequence Diagram: Iteration


Sequence Diagram: Alternate Message

Reception


Sequence Diagram: Recursion


Example


Life line

Creation

Deletion

Example


Life line Activatio

n

iteration

Example


Life linecollective iteration

Example


Concurrent Branch

Example


Tips and Tricks: Return Type

• Two ways to show return type of a message


Tips and Tricks: Object Destruction


Tips and Tricks: Iteration (looping) with A Condition


Tips and Tricks: Optional/Conditional

Messages


Tips and Tricks: Conditional Messages (Mutual

Exclusive)


Tips and Tricks: Looping Using Explicit Notations


Tips and Tricks: Looping Using Implicit Notations


Tips and Tricks: Nesting of Frames


Tips and Tricks: Relating Interaction Diagrams (Using Ref) / Interaction

Occurrence


Tips and Tricks: Polymorphic Message


Tips and Tricks: State Invariant


Tips and Tricks: Parallel


Tips and Tricks: Negative Operator/Invalid Operation


Tips and Tricks: Critical Region/Atomic


Tips and Tricks: Decomposition


Tips and Tricks: Continuations


Tips and Tricks: Hard Timing Requirements


Tips and Tricks: Break Fragment


Collaboration Diagram• Collaboration diagrams provide another way to

model a scenario.• Shows the roles of objects and associations of

objects in an instance of collaboration• Focus on structures of the objects rather than

temporal sequence of operations• In a collaboration diagram, each object is

represented by an object icon, and links are used to indicate communication paths on which messages are transmitted

• Messages are presented in the same way as those in a sequence diagram; in fact, sequence diagrams and collaboration diagrams are semantically equivalent


Example: Telephone System


Example: Message with Durations


Example: Printing Transcripts


Example: from Java IO API


Example: ATM Machine The ATM prompts the user to insert a card The user inserts an ATM card The ATM prompts the user to input the PIN The user enters the PIN The ATM asks the bank consortium to verify the ATM

card number and PIN The bank consortium verifies the ATM card number and

PIN with bank The bank notifies the bank consortium that the PIN is

correct The bank consortium notifies the ATM the PIN is correct The ATM prompts the user to select a service The user selects the withdraw cash service The ATM prompts the user to enter the amount to

withdraw


Example: ATM Machine The user enters the amount to withdraw. The ATM asks the bank consortium to

process the request. The bank consortium forwards the request to bank.

The bank confirms the successful execution of the request to the bank consortium which in turn notifies the ATM that the request has been approved

The ATM displays the successful transaction screen, ejects card and then dispenses cash requested

The ATM shows the main menu to the user for selecting the next service


ATM Machine: Part1


ATM Machine-Part2


Soft-Drink Vending MachineSequence Diagram


Soft-Drink Vending MachineCollaboration Diagram


Example


Resources

• Chapter 4, Object-Oriented Technology: From diagram to code with Visual Paradigm for UML

• UML 2 Certification Guide• http://www.informit.com/articles/article.as

px?p=360441&seqNum=5• UML-2 in a nutshell, chapter 10• http://www.tracemodeler.com/gallery/• http://www.agilemodeling.com/artifacts/

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