Object oriented modeling class object diagrams
This presentation is the property of its rightful owner.
Sponsored Links
1 / 22

Object-oriented modeling Class/Object Diagrams PowerPoint PPT Presentation


  • 76 Views
  • Uploaded on
  • Presentation posted in: General

Object-oriented modeling Class/Object Diagrams. Karolina Muszyńska. Based on : http://www.csun.edu/~dn58412/IS431/IS431_SP13.html S. Wrycza, B. Marcinkowski, K. Wyrzykowski „Język UML 2.0 w modelowaniu SI”. Object Modeling – class/object diagrams. Static view - class/object diagrams

Download Presentation

Object-oriented modeling Class/Object Diagrams

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Object oriented modeling class object diagrams

Object-oriented modelingClass/Object Diagrams

Karolina Muszyńska

Based on: http://www.csun.edu/~dn58412/IS431/IS431_SP13.html

S. Wrycza, B. Marcinkowski, K. Wyrzykowski „Język UML 2.0 w modelowaniu SI”


Object modeling class object diagrams

Object Modeling – class/object diagrams

  • Static view - class/object diagrams

    • role

    • basic concepts

    • advanced concepts

    • examples


Class object diagrams role

Class/object diagrams - role

Class diagrams – kind of UML diagrams showing the static view of the system, constituting the basis for the future object-oriented database. Class diagrams depict the system’s object structure and show object classes that the system is composed of as well as the relationships between classes.

Object diagrams - they are similar to class diagrams but instead of depicting object classes they model actual object instances, showing the structure of the systems in a given moment of time.


Class diagrams types

Class diagrams - types

Conceptual diagram – class diagram including basic elements, using class, attributes and behavior names, which are clear and understandable for the user.

Implementation diagram – class diagram enriched by additional elements like data types, visibility, association classes, generalization relationships, or realizations.


Class object diagrams basic concepts

Class/object diagrams – basic concepts

Object – anything that is or is capable of being seen, touched, or otherwise sensed, and about which users store data and associate behavior(which is important in the considered domain)

Attributes - data that represents characteristics of interest about an object (everything what is known about an object is represented by the attributes)

Behavior/Methods - refers to things that the object can do and that correspond to functions that act on the object’s data (or its attributes)

Class - a set of objects sharing a common structure – attributes and behavior, and common relationships and meaning.


Class object diagrams basic concepts1

Class/object diagrams – basic concepts

Class

Class name

Attributes with data types

Methods with output data types


Class object diagrams basic concepts2

Class/object diagrams – basic concepts

Object

Object name

Values of the attributes


Class object diagrams basic concepts3

Class/object diagrams – basic concepts

An object/classrelationship is an association that exists between one or more objects/classes. It is defined by business rules and/or common practices. There are four types of relationships among classes: association, generalization, dependency and realization.

Association - main type of relationship describing the possible set of associations among objects of the associated classes.

Navigation is the defined direction of communication between classes; if not defined the default navigation is bi-directional.

Multiplicity defines how many instances of one class can be associated with one instance of another class.


Uml multiplicity notations

UML Multiplicity Notations

UML

Multiplicity

Association

Multiplicity

Association with Multiplicity

Meaning

Notation

Works for

1

Employee

Department

An employee

1

Exactly 1

works for one

and only one

department.

Employee

Department

Zero or one

0..1

An employee has

Has

0..1

Employee

Spouse

either one or no

spouse.

Makes

0..*

Customer

Payment

0..*

A customer can

make no payment

Zero or

or

more

up to many

*

Makes

Customer

Payment

payments.

*

One or more

1..*

A university

Offers

offers at least 1

1..*

University

Course

course up to

many courses.

7..9

Has

A team has either

scheduled

7..9

Specific

Team

Game

7, 8, or 9 games

range

scheduled


Class object diagrams basic concepts4

places

0..*

Customer

Order

Class/object diagrams – basic concepts

Association name

Association

1

Multiplicity

Multiplicity

Roles

Roles

contractor

contract


Class object diagrams basic concepts5

Class/object diagrams – basic concepts

  • Aggregation – a special kind of relationship, which shows that some objects/classes are made up of other objects/classes. By identifying aggregation relationships we can partition a very complex object and assign behaviors and attributes to the individual objects within it. There are two types of aggregation relationships:

    • composition - all part-objects make up and live in the whole-object,

    • shared aggregation/aggregation/ - implies that parts may be shared by many wholes.


Object oriented modeling class object diagrams

AggregationRelationship

Operation Team

Doctor

Nurse

Admin staff

“is a part of” relationships

(part-objects may be shared by many whole-objects)


Object oriented modeling class object diagrams

Composition Relationship

Order

Book

Order item

Page

“is made of” relationships

(all part-objects make up and live in the whole-object)


Object oriented modeling class object diagrams

Class/object diagrams – advanced concepts

  • Visibility – access modifier which determines the access level of the attributes or methods of the object class. Visibility defines whether attributes and methods of specific classes can be seen and used by other classes. UML specifies 4 main visibility levels:

    • „-” private – only objects within the same class can see and use the attributes or methods,

    • „#” protected – only objects within the same class and from descendent classes can see and use the attributes or methods,

    • „+” public – objects of any class can see and use the attributes or methods,

    • „~” package - only classes within the same package can see and use the attributes or methods.

  • There is a rule that class attributes should be set private and the external access to them is made possible by public methods.


Class object diagrams advanced concepts

is seller

Participant

Auction

Class/object diagrams – advanced concepts

is buyer

Multiple association – a situation when associated classes can play different roles to each other and so there are multiple associations between them. Each association should be named or characterized.


Class object diagrams advanced concepts1

Class/object diagrams – advanced concepts

1

platform

Automobile

1..10

passenger car

transports

Reflexive association – a situation when there is an association between different objects of the same class (an association binding the class with itself).


Object oriented modeling class object diagrams

Class/object diagrams – advanced concepts

Generalization relationship - indicates that one of the two related classes - the subclass (child) is considered to be a specialized form of the other - the superclass (parent) and superclass is considered as ‘generalization'of subclass. In other words the child class is a specific type of the parent class and assumes all the characteristics of its parent class.

The generalization relationship is also known as the inheritance relationship.

The parent class can be either a real class or an abstract class. The abstract class has no real object instances, it is only a generalization of real objects which are specified as child classes.


Object oriented modeling class object diagrams

Generalization Relationship

Employee

Doctor

Nurse

Admin staff

  • “is a kind of” relationships


Class object diagrams advanced concepts2

Class/object diagrams – advanced concepts

Realizationrelationship - denotes the implementation of the functionality defined in one class by another class (interface). Relationship in which one model element (the client) realizes (implements or executes) the behavior that the other model element (the supplier) specifies. A realization relationship between classes and interfaces shows that the class realizes the operations offered by the interface.

Realizations can only be shown on class or component diagrams.


Class object diagrams advanced concepts3

Class/object diagrams – advanced concepts

Interface

Realization relationship


Building a class diagram

Building a Class Diagram

Find the potential objects (the best way is to review each use case to find nouns that correspond to business entities or events).

Select the proposed objects (clean the list of all potential business objects from: synonyms, nouns outside the scope of system, nouns that are roles without unique behavior or are external roles, unclear nouns that need focus and nouns that are really actions or attributes).

Identify attributes and operations of the classes.

Identify associations and multiplicity (to help insure that all possible relationships are identified we can create a class matrix).

Identify generalization relationships (we should look for all one-to-one multiplicity relationships between objects because they may be generalization relationships, as well as for classes that have common attributes and behaviors).

Identify aggregation relationships (we must remember that aggregation relationships do not imply inheritance but they propagate behavior).

The first step should be to identify related classes and build class diagrams for each particular use case and next build an integrated class diagram for the whole system.


Class diagram example

Classdiagram– example


  • Login