Building Blocks of UML

  Outline

• Unified Modeling Language

  Object-Oriented Modeling

• Principles and Concepts • Modeling Relations and Structures • Modeling Relations and Structures oleh:
• Modeling Dynamic Behavior

  I Gede Made Karma

• Modeling Requirements with Use Cases

  Object-Oriented Modeling Using UML

  2 What is a Model? Why We Model

  “A successful software organization is A model is a simplification of reality. one that consistently deploys quality A model may provide software that meets the needs of its

• – blueprints of a system blueprints of a system

  users. An organization that can A i ti th t

• – Organization of the system

  develop such software in a timely and

• – Dynamic of the system

  predictable fashion, with an efficient and effective use of resources, both human and material, is one that has sustainable business.”

  Object-Oriented Modeling Using UML

  3 Object-Oriented Modeling Using UML

  4 Why We Model Why We Model

• Model is buil
• We build models so that we can see
• – Communicate the desired structure and

  and better understand the system we behavior of the system are developing. p g

• – Visualize and control the system’s architecture Vi li d t l th t ’ hit t
• – Better understand the system that being built
• – Manage risk
• – Expose opportunities for simplification and reuse

  Object-Oriented Modeling Using UML

  5 Object-Oriented Modeling Using UML

  6 Principles of Modeling

• The choice of what models to create has a major influence on how a problem is approached and how a solution is shaped.
• Every model may be expressed at
• Models help us
• – to visualize a system as it is or as we want it to be.
• – to specify the structure or behavior of a system.
• – in providing a template that guides us in constructing a system.
• – in providing documenting the decisions we have made.
• The best models are connected to reality.
• No single model is sufficient. Every nontrivial system is best approached through a small set of nearly independent models.

  Object-Oriented Modeling Using UML

  12

  Object-Oriented Modeling Using UML

  Principles and Concepts

  11

  Object-Oriented Modeling Using UML

  Building Blocks of UML

  10 Specifying

  What is UML?

• Two most common ways in modeling software systems are
• UML is a language for
• – Visualizing – Specifying
• – Algorithmic
• Procedures or functions
• – Constructing – Documenting
• – Object oriented
• Objects or classes

  Object-Oriented Modeling Using UML

  Objected-Oriented Modeling

  8 y y p different levels of precision.

  Object-Oriented Modeling Using UML

  7

  f h b h f Object-Oriented Modeling Using UML

  Importance of Modeling

9 Algor thm c

• Things -- abstraction
• Relations -- tie things together
• Diagrams group interesting
• Objects and Classes • Principles
• Diagrams -- group interesting collections of things
• The state of an object is composed of a set of fields (data fields), or attributes.
• Each field has a name, a type, and a value.

• Each method has a name, a type, and a value.
• Each method may or may not return a value.
• Features are a combination of the state and the behavior of the object.

• Two objects are equal if their states are equal.
• Two objects are identical if they are the same objects.
• A class defines a template for creating or instantiating its instances or objects.
• A class is a description of a set of objects that share the same attributes, operations, relationships, and semantics.
• Methods that do not modify the state of the object are called accessors.
• Methods that modify the state of the object are called mutators.
• Objects can be mutable or immutable.
• A class defines --
• – the names and types of all fields
• – the names, types, implementations of all methods
• The values of the fields are not defined or fixed in the class definition.
• Each instance of the class has its own state.
• Different instances of the class may have different states.
• The implementations of methods are defined in the class definition and fixed for a given object.
• Values of methods are immutable

  (int dx, int dy){ // implementation

  18 p

  Object-Oriented Modeling Using UML

  Class name: Point class Point { Fields: x, y int x, y; Method: move public void move

  Example

  17 • The values of the fields are mutable.

  Object-Oriented Modeling Using UML

  Classes

  j

  16

  Object-Oriented Modeling Using UML

  Classes

  15 j • The values of the fields are mutable.

  Object-Oriented Modeling Using UML

  Properties of Objects

  f m , yp , • Behaviors are defined by methods.

  14

  Object-Oriented Modeling Using UML

  Objects • Each of object has a unique identity.

  A class characterizes the structure of states and behaviors that are shared by all instances.

  A class represents a set of objects with similar characteristics and behavior. This objects are called the instances of the class.

  Class

  13 y

  Object-Oriented Modeling Using UML

  An object has an identity, a state, and a behavior.

  An object is a thing that can be distinctly identified.

  Objects and Classes Interpretation in the Real World Interpretation in the Model Object

  }

• The name of the field is required in the field declaration.
• Field declaration may include:

  Private Student students[0..MAX_Size]

  21

  protected protected # package ~ private private -

  Examples

  Java Syntax UML Syntax Object-Oriented Modeling Using UML

  22 Date birthday Birthday:Date

  Public int duration = 100 +duration:int = 100

  Method Declaration

  Visibility syntax in Java and UML Visibilty Java Syntax UML Syntax public public +

  Object-Oriented Modeling Using UML

  [Visibility][Type]Name([Parameter, ...]) [Visibility]Name([Parameter, ...])[:Type]

  Examples

  Java Syntax UML Syntax Object-Oriented Modeling Using UML

  24

  void move(int dx, int dy) ~move(int dx, int dy) public int getSize() +int getSize()

  Object-Oriented Modeling Using UML

  [Visibility]Name[[Multiplicity]][:Type][ InitialValue]

1 The middle compartment

• Visibility or accessibility defines the scope:
• – Public -- the feature is accessible to any class
• – Protected -- the feature is accessible to the class itself, all the classes in the same package, and all its subclasses.
• – Package -- the feature is accessible to the class itself and all classes in the same package.
• – Private -- the feature is only accessible within the class itself.

  20

  UML Notation for Classes

  ClassName The top compartment shows the class name. field

  Object-Oriented Modeling Using UML

  19

  1

  … field

  n

  The middle compartment contains the declarations of the fields of the class. method

  1

  … method

  m

  The bottom compartment contains the declarations of the methods

  Field Declaration

  [Visibility][Type]Name[[Multiplicity]][=InitialValue] [Visibility]Name[[Multiplicity]][:Type][=InitialValue]

  Object-Oriented Modeling Using UML

• students[0..MAX_Size]:Student
• The name of the method is required in the method declaration.
• Method declaration may include:
• Each parameter of a method can be specified by -- Type Name

23 Method declaration may include:

• x:int
• y:int Object-Oriented Modeling Using UML
• move(dx:int,dy:int)

  Object-Oriented Modeling Using UML

  Object-Oriented Modeling Using UML

  Java.awt.event javax.swing.*

  Packages

  Method move() Arguments (10,20)

  29 p1.move(10,20)

  Recipient p1 Object-Oriented Modeling Using UML

  Example

  to an object -- recipient

  28 A message represent a command sent

  Object-Oriented Modeling Using UML

  Message Passing or Method Invocation

  P1.y = 40;

  27 y = 0 P1.y = 0; P1:Point Point p1 = new Point(); x = 24 y = 40 p1.x = 24;

  P1:Point Point p1 = new Point(); x = 0 p1.x = 0; P1

  Examples

  The bottom compartment contains a list of the fields and their values. objectName -- objectName whose class is of no interest :ClassName -- anonymous object of ClassName which can be identify only through its relationship with other object.

  = value n

  1 … field n

  1 = value

  field

  26

  1 Object-Oriented Modeling Using UML

  1 = value

  UML Notation for Object ObjectName : ClassName The top compartment shows the object name and its class. field

  Point x y move()

  25 private int x private int y public void move(int dx,int dy)

  Point Point

  Example

• Objects communicate with one another through message passing.
• A message represent a command sent
• A message consists of the receiving object, the method to be invoked and the arguments to method.
• Package name are in lower case --
• Packages that will be widely used should be named as the reverse of the internet domain as the prefix of the package name -
• EDU.emporia.mathbeans.MathTable EDU.emporia.mathtools.*

  30 UML notation of packages

• Modularity:
• – alleviate complexity of large-scale systems
• Abstraction:
• – separating the essential from the non-essential
• Encapsulation:
• – Information hiding
• Polymorphism:
• – Portability
• Levels of Abstraction:
• – Organization of classes and interfaces

  p g characteristics of an entity

  Object-Oriented Modeling Using UML

  Object-Oriented Modeling Using UML

  32

31 Principles

  Principle of Modularity

  Object-Oriented Modeling Using UML

  33 coupling.

  Principle of Abstraction

• A complex software system should be decomposed into a set of highly cohesive but loosely coupled modules.
• The basic for decomposition are cohesion and
• The behaviors or functionalities should be precisely characterized as contractual interface which captures
• – Cohesion -- functional relatedness of the entities within modules.
• – Coupling – inter-dependency among different modules.
• The complexity of the module is hidden from the clients.
• Each module is relatively small and simple
• Interactions among modules are relatively simple
• hierarchical
• The implementation of a module should be separated from its contractual interface and hidden
• Ability to interchange modules dynamically without affecting the system.
• refers to a contractual interface with multiple interchangeable implementation
• Information hiding

  34

  p the essence of the behavior.

  Principle of Encapsulation

  Object-Oriented Modeling Using UML

  35 from the clients of the module.

  Principle of Polymorphism

  Object-Oriented Modeling Using UML

  36

  y

  Object-Oriented Modeling Using UML

• Define a relationship among classes and interfaces
• Inheritance model -- the is-a(n) relationship
• A class diagram consists of
• – A set of nodes that represent classes and interfaces A t f li k t l ti hi
• – A set of links represent relationships among classes
• Class diagrams can be used to model:
• – Inheritance -- extension and implementation
• – Association -- aggregation and compostion
• – Dependency

  Object-Oriented Modeling Using UML

  Object-Oriented Modeling Using UML

  1

  1

  Faculty advisee adviser

  41 Student Course

  Object-Oriented Modeling Using UML

  Association

  40 Higher level is more general

  Abstraction

• Abstractions can be organized into different levels.
• Higher level is more general
• Aggregation is a special form of association
• Association represents binary relationship between classes
• – Has-a or part-whole relationship
• Composition is a stronger form of aggregation
• enroll teach
• enroll *
• Aggregation and Compositon
• Dependency is a relationship between entities such that the proper operation of one entity depends on the presence of the other entity and

  39 Principle of Levels of

  Object-Oriented Modeling Using UML

  relationship Example

  38

  Object-Oriented Modeling Using UML

  Inheritance

  37

  Object-Oriented Modeling Using UML

  Modeling Relationships and Structures

  42 gg g

  2 Graphical notations

  Example Registrar CourseSchedule

  exit/Action

  1

  [Event-List][[Guard]][/Action]

  48 p

  Object-Oriented Modeling Using UML

  47 Modeling Dynamic Behavior

  46 Example Object-Oriented Modeling Using UML

  Object-Oriented Modeling Using UML

  Student Modeling Dynamic Behavior

  void addCourse(CourseSchedule a, Course c) void removeCourse(CourseSchedule Course findCourse(String title) void enroll(Course c, Student s) void drop(Course c, Student s Course

  45

  Object-Oriented Modeling Using UML

  the presence of the other entity, and changes in one entity would affect the other entity.

  44

  Object-Oriented Modeling Using UML

  1 1 1..* Dependency

  1

  1

  1

  1

  Faculty Chairman-of Member-of

  43 University Department

  1 Object-Oriented Modeling Using UML

  1

  1

  Example

• College Student *

• Sequence diagram
• – Depict object interaction by highlighting the time ordering of method invocation
• State diagram
• – Depict the flow of control using the concepts of state and transitions
• – Labels of transitions are in the form:
• Entry action and exit action entry/Action

• Nested state diagram
• – Composite of state diagrams

  Object-Oriented Modeling Using UML

  Object-Oriented Modeling Using UML

49 Modeling Dynamic Behavior

  50 Example Object-Oriented Modeling Using UML

• Use cases describes the externally observable behavior of system functions in the form of interactions between the system to be developed and the external
• Actors may represent roles played by users of the system or other systems.
• Consist of a name and scenarios
• One of scenarios is the main scenario

  51

  talk Modeling Requirements with Use Cases

  52 system to be developed and the external entities -- Actors.

  Use Case Diagram

• Consist of:
• – Use cases
• – Actors – Relationships among actors and use cases

  Object-Oriented Modeling Using UML

  53 p g

  Extension relationships among actors

  Object-Oriented Modeling Using UML

  54

  Object-Oriented Modeling Using UML

• Problem requirements
• Program specifications
• Object models
• – Identifying classes
• – Identifying the features of classes -- states and behaviors
• – Identifying relationships among classes – inheritance and interfaces.
• Provide information on the books, CDs, and software
• Provide a functionality for customers registration as well as updating customer’s
• Allow customers to browse and order books, music CDs, and computer software
• Provide a functionality for ordering and shipping
• Provide a functionality for updating inventory

  58 registration as well as updating customer s information

  System administrator Inventory manager

  Acount Process order g

  59 Manage

  Object-Oriented Modeling Using UML

  Logon Customer Manager

  Register Shop Manage catalog

  Object-Oriented Modeling Using UML

  Dependency relationships among use cases

  57 Specifications

  Object-Oriented Modeling Using UML

  Requirements

  56 Object models

  Object-Oriented Modeling Using UML

  55 Case Study: An E-Bookstore

  Object-Oriented Modeling Using UML

  Catalog Manager