Object Oriented Technic Notes(Unit2)

7/30/2019 Object Oriented Technic Notes(Unit2)

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Structural Modeling:Structural Modeling:Structural Modeling:Structural Modeling:

Structural modeling is a view of a system that shows the structure of the objects,

including their classifiers, relationships, attributes and operations.

Structural Model represents the framework of the system and this framework is theplace where all other components exist.

Class diagram, component diagram, and deployment diagrams are the part of structural

modeling.

Structural model never describes the dynamic behavior of the system.

Structural modeling consist of the following

Class Diagram

Object Diagram

Deployment Diagram

Package Diagram

Composite structure Diagram

Component Diagram

Links,Links,Links,Links, associationassociationassociationassociation and otherand otherand otherand other concepts:concepts:concepts:concepts:

Links:Links:Links:Links:

A Link is a physical or conceptual connection among objects

Used in object diagram and class diagram

Type of Links:

1. One to one

2. One to many

3. Many to One

4. Many to Many

Association:Association:Association:Association:

It can be shown by a line and defines relationship between two or more classifiers that

involves connections among their objects.

An association can be named, and the ends of an association can be adorned with role

names, ownership indicators, multiplicity, visibility, and other properties.


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Types of associationTypes of associationTypes of associationTypes of association

1. AAAA Unary associationUnary associationUnary associationUnary association if a class associated with itself

2. A Binary associationBinary associationBinary associationBinary association exist between 2 classes appears as a straight line

3. TernaryTernaryTernaryTernary AssociationAssociationAssociationAssociation

3.3.3.3. Quarternary AssociationQuarternary AssociationQuarternary AssociationQuarternary Association

MultiplicityMultiplicityMultiplicityMultiplicity::::

The association relationship indicates that (at least) one of the two related classes

makes reference to the other.

The UML representation of an association is a line with an optional arrowhead

indicating the roleof the object(s) in the relationship, and an optional notation

at each end indicating the multiplicityof instances of that entity (the number of

objects that participate in the association).

0..10..10..10..1 No instances, or one instance (optional, may)

1111 Exactly one instance

0..*0..*0..*0..* or **** Zero or more instances

1..*1..*1..*1..* One or more instances (at least one)


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Many(zero or more)

Optional(zero or one)

Exactly One

1+ One or more

Realization:Realization:Realization:Realization:

A realization relationship is a relationship between two model elements, in which one

model element (the client) realizes (implements or executes) the behavior that the othermodel element (the supplier) specifies. A realization is indicated by a dashed line with

an unfilled arrowhead towards the supplier.

Realizations can only be shown on class or component diagrams.

A realization is a relationship between classes, interfaces, components, and packages

that connects a client element with a supplier element

Generalization:Generalization:Generalization:Generalization:

A Generalization appears as a line with an open Triangle at one end.

Generalization refers to a relationship between a general class(parent class) and a more

specific version of that class(child class)

The generalization relationship is also known as the inheritanceor "is a"relationship.


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Role Name:Role Name:Role Name:Role Name: Role name is a name that uniquely identifies one end of an association.

Ordering:Ordering:Ordering:Ordering:defines order in { }

Qualification:Qualification:Qualification:Qualification: A Qualified association relates two object classes and a qualifiers.

The qualifier is a special attribute that reduces the effective multiplicity of an association.


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ClassClassClassClass diagramdiagramdiagramdiagram

A class diagramclass diagramclass diagramclass diagram in the UML is a type of static structure diagram that describes the

structure of a system by showing the classes of system, their attributes, operations (or

methods), and the relationships among the classes. These static aspects represents those parts of a diagram which forms the main structure

Class diagrams are used in modeling of object oriented system because they are the only

UML diagrams which can be mapped directly with object oriented language.

A class with three sections.

The upper part holds the name of the class

The middle part contains the attributes of the class

The bottom part gives the methods or operations of the class

Purpose of Class Diagram:Purpose of Class Diagram:Purpose of Class Diagram:Purpose of Class Diagram:

Analysis and design of the static view of the system.

Describe responsibilities of a system

Shows the collaboration among the elements of a system

Base for component and deployment diagram.

Creating a Class Diagram:Creating a Class Diagram:Creating a Class Diagram:Creating a Class Diagram:

For creating a class diagram we need Classes, responsibilities, association,

inheritance, interface, and composition.

Core ElementsCore ElementsCore ElementsCore Elements

Class:Class:Class:Class: a description of a set of objects that share the same attributes, operations, methods,

relationships and semantics.


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Interface:Interface:Interface:Interface: a named set of operations that characterize the behavior of an element.

Component:Component:Component:Component: a physical, replaceable part of a system that packages implementation andprovides the realization of a set of interfaces.

NNNNodeodeodeode can be defined as a physical element that exists at run time .It is a run-time physical

object that represents a computational resource, generally having at least some memory and,

often, processing capability

Core Relationships:Core Relationships:Core Relationships:Core Relationships:

AssociationAssociationAssociationAssociation:

It can be shown by a line and defines relationship between two or more classifiers that

involves connections among their objects.

An association can be named, and the ends of an association can be adorned with rolenames, ownership indicators, multiplicity, visibility, and other properties.

It can be bi-directional, uni-directional etc.

Aggregation:Aggregation:Aggregation:Aggregation:

An aggregation appears as a line with an open diamond at one end.

A special form of association that specifies a whole-part or part-of relationshipbetween the aggregate (whole) and the component part.

It is more specific than association.


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Generalization:Generalization:Generalization:Generalization:

A Generalization appears as a line with an open Triangle at one end.

Generalization refers to a relationship between a general class(parent class) and a more

specific version of that class(child class)

The generalization relationship is also known as the inheritance or "is a"relationship.

Dependency:Dependency:Dependency:Dependency: A relationship between two modeling elements, in which a change to one

modeling element (the independent element) will affect the other modeling element ( the

dependent element).

Object Diagram:Object Diagram:Object Diagram:Object Diagram:

Object diagrams are derived from class diagrams.

It shows a set of objects and their relationships just like class diagram and also represent

the static view of the system.

Static view is a snapshot of the system at a particular moment.

It is a diagram that shows a complete or partial view of the structure of a modeled

system at a specific time.

The usage of object diagram is similar to class diagrams but they are used to build

prototype of a system.

Object diagrams are more concrete than class diagrams, and are often used to provide

examples, or act as test cases for the class diagrams.


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Only those aspects of a model that are of current interest need be shown on an object

diagram.

To create a object in UML we use a box with an object name followed by a colon (:) and then

the class name;

Object diagram focus on set of objects, attributes, and relationship between the objects.

Ex:Ex:Ex:Ex:---- Class DiagramClass DiagramClass DiagramClass Diagram Object DiagramObject DiagramObject DiagramObject Diagram


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Collaboration DiagramCollaboration DiagramCollaboration DiagramCollaboration Diagram:::: A collaboration diagrams focus on the relationships between objects.

It allows the designer to specify the sequence of messages sent between objects in

collaboration, this diagram does not show the life time of the objects.

In it the event/method call sequence is indicated by sequence number preceding

messages. The number indicates how the methods are called one after another.

The method calls are similar to sequence diagram but the difference is that the sequence

diagram does not describe the object organization whereas the collaboration diagram

shows the object definition.

In this the sequence of events are indicated by numbering.

Also known as interaction diagram.

It requires use case, system operation contracts, and domain model to already exist.

They are composed of three elements.1. Objects

2. Associations

3. Messages

Placement of colon indicate either a objectName:,objectName:,objectName:,objectName:, or a :className:className:className:className.

Order management systemOrder management systemOrder management systemOrder management system


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Sequence diagram:Sequence diagram:Sequence diagram:Sequence diagram: Sequence diagrams contain the same information as Collaboration diagrams, but

emphasize the sequence of the messages instead of the relationships between the

objects.

Sequence diagrams focus on the order in which the messages are sent. It shows how the

objects communicate with each other in terms of sequence of messages

It shows a set of objects and the messages sent and received by those objects.

An object in a sequence diagram is rendered as a box with a dashed line descending

from it.The line is called the object lifeline, and it represents the existence of an object

over a period of time.

Messages are rendered as horizontal arrows being passed from object to object.

Conditions such as check=true indicate when a message gets passed.

Type of Message:Type of Message:Type of Message:Type of Message:

Synchronous MessageSynchronous MessageSynchronous MessageSynchronous Message is a message sanded by sender to receiver and sender object waits

until the receiver object finish its processing of message, shown by a solid line with an

open arrowhead

Asynchronous messageAsynchronous messageAsynchronous messageAsynchronous message sender object does not wait for receiver object to finish its

processing of message. All messages maintains a message queue and sanded according

to its priority,

Return messageReturn messageReturn messageReturn message uses a dashed line with an open arrowheadLost messageLost messageLost messageLost message that does not reach its destination, shown by a solid line with an open

arrowhead with a black dot

Found messageFound messageFound messageFound message (a message whose sender is not found) that originate at an endpoint

symbol (black dot)


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Component DiagramsComponent DiagramsComponent DiagramsComponent Diagrams

Component Diagrams show the types of software components in the system, their

interfaces and dependencies.

Component diagrams address the static design implementation view of a system

They are important for building large systems from smaller parts.

It provides a physical view of a system.

Main purpose of component diagram is to show the dependencies of the components in

the system.


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Basic Behavioral Modeling:Basic Behavioral Modeling:Basic Behavioral Modeling:Basic Behavioral Modeling:

Any system can have two aspects, static and dynamic. So a model is considered as

complete when both the aspects are covered fully.

Behavioral model basically capture the dynamic aspect of a system. Dynamic aspect can

be further described as the changing/moving part of a system.

Behavioral model describes the behavior or functionality of the system.

Basic behavioral models are

1. Use case diagram

2. Activity diagram

3. State chart diagram

Use CaseUse CaseUse CaseUse Case Diagram:Diagram:Diagram:Diagram:

Use case diagrams are set of use cases, actors and their relationships.

Use case represents a particular functionality of a system.

So use case diagram is used to describe the relationships among the functionality

and their internal/external controller. These controllers are known as actors.

Actor is an external user of the system.

Use case describes action between actor and software system.

Helps to achieve the goal of the system. The symbols used to create use case diagram are

1. ActorsActorsActorsActors (stick men) are anything outside the system that

interacts with the system.

2. Use Cases (ovals) are the procedures by which the actors interact

with the system.

3. Solid lines indicate which actors interact with the system as part of

which procedures.

4. Dashed lines show dependencies between use cases, where one use

case is 'included' in or 'extends' another.


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EX:EX:EX:EX:----Use case diagram for vending machineUse case diagram for vending machineUse case diagram for vending machineUse case diagram for vending machine

Activity Diagram:Activity Diagram:Activity Diagram:Activity Diagram:

Active diagram describes the flow of control in a system. So it contains of activities and

links.

The flow can be sequential, concurrent etc.

Activities are nothing but the functions of a system.

Numbers of activity diagrams are prepared to capture the entire flow in a system.

This is prepared to have an idea of how the system will work when executed.

Activity diagram focus on operations rather than objects.

Different terms in activity diagramDifferent terms in activity diagramDifferent terms in activity diagramDifferent terms in activity diagram:

1. Active statesActive statesActive statesActive states - oblongs with rounded corners which describe what is done or executionof an action

2. TransitionsTransitionsTransitionsTransitions when an action or activity of a state complete.

3. ConditionsConditionsConditionsConditions ---- (in square brackets) which qualify the transitions, or shows the decision

point

4. Branch:Branch:Branch:Branch: shows the path

5. Concurrent activity:Concurrent activity:Concurrent activity:Concurrent activity: When two or more activities are performed parallel.


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ExampleExampleExampleExample :::: Activity diagram for the process of stock trade order

State chart Diagram:State chart Diagram:State chart Diagram:State chart Diagram:

Any real time system is expected to be reacted by some kind of internal/external events.

These events are responsible for some change of the system.

State chart diagram is used to represent the event driven state change of a system.

It basically describes the state change of a class, interface etc.

State chart diagram is used to visualize the reaction of a system by internal/external

factors.

o Initial state

o Final state

State


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TransitionsTransitionsTransitionsTransitions - the solid arrows which show possible changes of state.

Events - the text on the transitions before the '/' showing the incoming call to the

object interface which causes the change of state.

ConditionsConditionsConditionsConditions - a boolean statement in square brackets which qualifies the event.

ActionsActionsActionsActions - the text after the '/' which defines the objects response to the transition

between states.

Extra syntax which defines state-centric functionality

Ex: motor systemEx: motor systemEx: motor systemEx: motor system


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Package Diagram:Package Diagram:Package Diagram:Package Diagram:

Package diagram in UML can be shown as dependencies between the packages that

make a model. There are 2 type of dependencies b/w package

1. Package import

2. Package merge

By default dependencies b/w two packages is implement as the package import

relationship.

A package merge relationship shows the contents of two packages are combined.

It is similar to generalization.

EX:EX:EX:EX:

Package

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Object Oriented Technic Notes(Unit2)