UML UML IntroductionIntroduction

Frameworks and Design PatternsFrameworks and Design Patterns

Alexandre Lomovtsev, Natalia Shatokhina

John Hautzinger, Sae Rom Hong

CS537 – Fall 2010

CSULA

UML UML IntroductionIntroduction

Alexandre Lomovtsev, Natalia Shatokhina

What is UML?What is UML?

is a complete Language for capturing knowledge (semantics) about a subject and expressing knowledge (syntax) regarding the subject for the purpose of communication

applies to Modeling – process of understanding a subject (or a system)

is Unified – remaining the same at each stage of development

BackgroundBackground

1965 - the first object-oriented programming language, Simula I, was introduced

Object-oriented design began to rapidly grow

Numerous competing object-oriented design methods and modeling languages over 50 modeling languages

Dominate modeling Dominate modeling methodsmethods Object-oriented Analysis & Design (OOAD)

by Grady Booch

The Object Modeling Technique (OMT) by James Rumbaugh

The Object-oriented Software Engineering method (OOSE) by Ivar Jacobson

Booch (OOAD)Booch (OOAD)

Very complex The modeling language has too many types

of diagrams and diagram elements

Effective at low-level design Useful for documenting code

Good at OO Design, weak at OO Analysis

Rumbaugh (OMT)Rumbaugh (OMT)

A simpler modeling language Better at higher-level designs than Booch’s

Method.

Good at OO Analysis, weak at OO Design

OO Analysis vs. OO DesignOO Analysis vs. OO Design

Analysis refers to understanding the problem.

Design refers to coming up with the solution.

REQUIREMENTSand

ANALYSIS

DESIGN

IMPLEMENTATION

TESTING

Jacobson (OOSE)Jacobson (OOSE)

Major feature was "use classes" how a system interacts with users (other

systems or end users) Viewing things from the user’s perspective

Good at very high-level design

In summaryIn summary

Jacobson (OOSE) good at high-level design

Rumbaugh (OMT) good at the middle ground

Booch (OOAD) good at low-level design

ChronicsChronics of the UML of the UML1994 : Booch + Rumbaugh = Unified Method 0.8

1995 : + Jacobson = UML 0.8

Receiving a feedback from IBM, Microsoft, Oracle, HP and other companies

1996 : UML 0.9

1997 : UML 1.0

Object Management Group (OMG) joined UML project

1997 : UML 1.1

UML is running under the OMG Revision Task Force

Improving semantics and flexibility

2003 : UML 2.0

Standards bloat size of UML specification is dramatically increased too many diagrams that are redundant or

infrequently used problem in learning and adopting

The extremely poor writing of the UML standards themselves

written by a non-native English speakers an example of unintelligible geek-speak

UML and implementation language mismatch an intersection set between UML and

implementation language is very small

CriticismsCriticisms

Dysfunctional interchange format

The XMI (XML Metadata Interchange) standard is large and complex

The UML’s main purpose is not being an interchange format between modeling tools.

A lot of modelers who don't want to redraw their diagrams

Criticisms (cont.)Criticisms (cont.)

UML 2.0 diagramsUML 2.0 diagrams

ClassDiagram

ObjectDiagram

ComponentDiagram

CompositeStructureDiagram

PackageDiagram

Deployme ntDiagram

UseCase

Diagram

ActivityDiagram

StateMachineDiagram

SequenceDiagram

CommunicationDiagram

TimingDiagram

InteractionOverviewDiagram

Structure Diagrams Behavior Diagrams Interaction Diagrams

UML 2.0 ElementsUML 2.0 Elements

Behavioral Diagram Elements State Use Case Package …

Structural Diagram Elements Class Object Interface …

UML 2.0 ElementsUML 2.0 Elements

Links Composition Link Unidirectional Association Link Bidirectional Association Link Generalization Link

Multiplicity 0..1 No instances, or one instance 1 Exactly one instance 0..* Zero or more instances 1..* One or more instances (at least one)

Structural diagramsStructural diagramsClass diagramClass diagram

Class diagram gives a static view of the system EXAMPLE Modeling a family tree - this model is similar to a class diagramTo build a model we need to: Identify the main members of the family (CLASSES) Determine how they are related to each other (HIERARCHY) Identify the characteristics of each family member (ATTRIBUTES) Find relations among any members (RELATIONSHIPS BTW CLASSES) Decide the inheritance of personal traits and characters (INHERITANCE)

A class diagram consists of a group of classes and interfaces reflecting important entities of the business domain of the system being modeled, and the relationships between these classes and interfaces.

In a typical software development life cycle class diagrams are made by senior developers with the help of system architects.

Class Diagram-ExampleClass Diagram-Exampleclass name

relationships

StereotypesStereotypes It is an extension of the existing UML

elements; it allows you to define new elements modeled on the existing UML elements.

Graphically, a stereotype is rendered as a name enclosed by angle brackets (<< >>) and placed above the name of another element. In addition or alternatively it may be indicated by a specific icon.

In a class diagram stereotypes can be used to classify method behavior for example as <<constructor>>.

Constructor stereotype indicates that the operations following it are constructors.

Key Manager

<<constructor>>- New ()

<<misc>>+ GetInstance(): KeyManager

Behavior diagramsBehavior diagramsUse case diagramUse case diagram

Captures functional aspects of a system The Use case diagram is used to identify the

primary elements and processes that form the system. The primary elements are termed as "actors" and the processes are called "use cases".

The Use case diagram shows which "actors" interact with each "use case".

This kind of diagrams are made by business or functional domain experts

Use case diagramUse case diagram

Elements: Actors: An actor portrays

any entity (or entities) that performs certain roles in a given system

Interactions

Use case: a visual representation of a distinct business functionality in a system

State machine diagramState machine diagram

Class and use cases diagrams are static which means that they help in visualizing what the elements of the complete system would be, but do not say anything about the flows any object of the system can have when an event occurs.

State diagrams are used to help the developer better understand any complex/unusual functionalities or business flows of specialized areas of the system. In short, State diagrams depict the dynamic behavior of the entire system, or a sub-system, or even a single object in a system.

A state diagram can be defined not only for a system or subsystem, but also for an object in the system.

A state machine diagram specifies the sequence of events that an object goes through during its lifetime in response to events.

As an example, the following state machine diagram shows the states that a door goes through during its lifetime.

Activitiesstate

State machine diagramState machine diagram

Activity diagramActivity diagram

An Activity diagram is a dynamic diagram that shows the activity and the event that causes the object to be in the particular state.

A State diagram shows the different states an object is in during the lifecycle of its existence in the system, and the transitions in the states of the objects.

An Activity diagram talks more about these transitions and activities causing the changes in the object states.

Activity diagramActivity diagram

Activity to model : Attending a lecture at 8 am

Activity steps: Get dressed Make decision if there is

enough time to take bus Take bus, or take taxi

depending on decision Arrive at school and attend

lecture

Initial state

Final state

In time for bus Not in time for bus

Take bus to school Take taxi to school

Attend lecture

Get dressed

Sequence diagramSequence diagram Shows object interactionShows object interaction over time

One of the most widely used dynamic diagrams in UML

A Sequence diagram depicts the sequence of actions that occur in a system. The invocation of methods in each object, and the order in which the invocation occurs is captured in a Sequence diagram.

Sequence diagramSequence diagram Two-dimensional:

Vertical axis - life of the object that it representsHorizontal axis - the sequence of the creation or invocation of these objects.

:CommsController :WeatherStation :WeatherData

request (report)

acknowledge()request ()

summarize()

send(report)reply (report)

acknowledge()Life line

Activation

Object

Actor

Structural components: Telephone Cellular radio Display Microphone Speaker Button Dialer

Communication diagramCommunication diagram

:Speaker

:Button :Dialer :Cellular radio

:Send:Button:Display

1*:Digit(code)

1.1:DisplayDigit(code)

2:Send()

2.1.1 :In Use()

2.1:Connect(pno)

1.2:EmitTone(code)

Diagram shows how several objects collaborate to get job done. Models object interactions and structural dependencies

Use case:

user makes a call

Example: Software system that controls simple cell phone

Structure diagrams for Structure diagrams for implementationimplementation

Component diagramComponent diagram

Component diagrams represent the implementation perspective of a system. Hence, components in a Component diagram reflect grouping of the different design elements of a system, for example, classes of the system.

Deployment diagramDeployment diagram The deployment diagram captures the configuration of

the runtime elements of the application and represents interactions between software and hardware.

The deployment diagram elements provide the necessary environment for the components to execute in.

The basic deployment diagram element is the node. The node represents the environment in which a component or a set of components execute.

Deployment diagram should start from the time when static design is being formalized using, say, class diagrams.

This deployment diagram evolves and is revised until the system is built.

Deployment diagramDeployment diagram

Example: University information system

nodes

Software development Software development phases phases and UMLand UML

Software lifecycle: Requirements definition

Use case diagrams Activity diagrams Sequence diagrams Communication diagram

System and software design and implementation Component diagrams Class diagram State diagram

Deployment Deployment diagram

Frameworks Frameworks and Design and Design

PatternsPatterns

John Hautzinger, Sae Rom Hong

Patterns and FrameworksPatterns and Frameworks

Classes Mechanism for encapsulation Provides a single service Rarely a complete solution

Application Frameworks and Design Patterns became popular solutions

Application FrameworksApplication Frameworks

Set of classes that cooperate with each other Together embody reusable design for a general

category of problems

Framework dictates the overall function and behavior of the application. Describes how responsibilities are partitioned

between various components and how they interact.

Application Frameworks Application Frameworks (Cont.)(Cont.) Application Frameworks became popular

with the rise of GUIs These tended to promote standard structures

Commercial Application Frameworks MacApp

First commercial application framework Microsoft Foundation Classes (MFC) Oracle Application Development Frameworks

Oracle ADF Aids in producing Java-oriented systems

Swing

Popular FrameworksPopular Frameworks

Swing Developed to provide a more sophisticated

set of GUI components than Abstract Window Toolkit (AWT)

Highly partitioned to allow extensibility  Users can provide their own custom

implementations of these components to override the default implementations

Highly Customizable, Configurable, and Lightweight

Popular FrameworksPopular Frameworks

Oracle Application Development Framework Java framework for developing enterprise

applications Supports rapid application development

using design patterns Supports many software frameworks

A Framework as an Upside-A Framework as an Upside-down Librarydown Library In a traditional application-specific code

defines overall flow of execution, occasionally invoking library-supplied code Frameworks reverse this relation

Flow of control is dictated by the Framework and the creator of a new application merely changes some of the methods invoked by the framework

Inheritance is often used for achieving this Alternatively application-specific components

that obey a specified interface are plugged in

Application Framework Application Framework ExamplesExamples GUI application frameworks simplify the

construction of graphical user interfaces A GUI application framework implements the

behavior expected from a graphical user interface Hold windows, buttons, menus, etc..

A new application is built by specifying and arranging necessary elements and modifying certain methods

Another AF ExampleAnother AF Example

Simulation frameworks simplify the creation of simulation style applications

Simulation frameworks provide general-purpose classes for managing the types of objects in the simulation

The heart of the simulation framework is a procedure that cycles through the list of objects introduced and asks each to update itself

The framework knows nothing of the particular application

Toolkits and FrameworksToolkits and FrameworksMain body of an application

Reuse the main body of anApplication and write the code it calls

Toolkit Framework

Calls a procedure or a method

Defines the architectureor the application

Toolkits: Collection of related and reusable classese.g. C++ I/O stream library

Framework: A set of cooperating classes thatmake up a reusable design for a specificclass of applications e.g. drawing, compilers,CAD/CAM etc.

Disadvantages of Disadvantages of FrameworksFrameworks May add to "code bloat"

Due to both competing and complimentary frameworks sometimes being needed

Some 'one size fits all' frameworks' add much unused code

Can be argued that frameworks may add to development time Developers must take time to learn the

framework

Questions about Questions about FrameworksFrameworks When using frameworks, what defines the

architecture of the application? In a traditional application the architecture of is defined

by the specific functional problem that the application needs to solve

Using a framework, in addition to the problem needing to be solved, the architecture is defined by the framework in use

What is more difficult to design: Application, toolkit, or frameworks? Frameworks are the most difficult to design, they

permeate the entire application and dictate its architecture.

Questions about Questions about FrameworksFrameworks How do changes in framework affect an

application? Since the framework permeates the application on

almost every level, major changes to the framework may change the way the application functions. This may result in changes that need to be made in the code and/or logic of the application

How do design patterns differ from frameworks? A design pattern is not a finished design that can be

transformed into code. It is a description or template for how to solve a problem that can be used in many different situations. Frameworks can be directly implemented into an application whereas design patterns

Design Design PatternsPatterns

Design Design Goals Goals Reusability, Flexibility, and Maintainability

Reuse flexible designs Keep code at a general level Minimize dependency on other classes

Robustness Reuse reliable designs Reuse robust parts

Sufficiency and Correctness Modularize design Reuse trusted parts

What are Design Patterns?What are Design Patterns?

Design patterns are an attempt to collect and catalog the smallest recurring architectures in object oriented software systems.

A design pattern expresses an idea rather than a fixed class combination

Design patterns are more abstract than a framework

It conveys an idea, however, not a completely specific design.

What are Design Patterns?What are Design Patterns?

Housing Preferences to a realtor

Ranch StyleSpanish Colonial

Style

Victorian House Style

BungalowStyle

Example how patterns express idea:

Design Patterns VS AlgorithmDesign Patterns VS Algorithm

Efficiency is used to describe properties of an algorithm relating to how much of various types of resources it consumes Speed Memory

Design Patterns is more related to relationships in OOP

Taxonomy of Design PatternsTaxonomy of Design Patterns

Purpose: depending upon whether it has to do with

Creational Design Creational Design PatternsPatterns Abstracts the instantiation process:

Encapsulates knowledge about which concrete classes to use

Hides how the instances of these classes are created and put together

Gives a lot of flexibility in what gets created, who creates it, how it gets created, and when it gets created

A class creational pattern uses inheritance to vary the class that is instantiated

An object creational pattern delegates instantiation to another object

Creational Design PatternsCreational Design Patterns

Design Pattern Name

Design Purpose Satisfied by this

Pattern

Summary of the Design Pattern

Factory MethodCreate objects at

runtime with flexibility Created desired

objects

Abstract FactoryCreate coordinated families of objects

Capture each family in a class

Prototype

Create an aggregate object in which

selected parts are essentially copies

Create the objects of the type cloning a

prototype

SingletonEnsure that a class has

exactly one instantiation

Make the constructor private and obtain the

unique object

Builder

Structural Design PatternsStructural Design Patterns Structural design patterns are concerned with

how classes and objects are composed to from larger structures

A class structural pattern uses inheritance to compose interfaces or implementation; compositions are fixed at design time

An object structural pattern describes ways to compose objects to realize new functionality; the added flexibility of object composition comes from the ability to change the composition at run-time

Structural Design PatternsStructural Design Patterns

Design Pattern Name

Design Purpose Satisfied by this

Pattern

Summary of the Design Pattern

Composite

Façade

Proxy

Flyweight

Adapter

Bridge

Decorator

Behavioral Design Behavioral Design PatternsPatterns Behavioral design patterns are concerned with

algorithms and the assignment of responsibilities between objects

Behavioral class patterns use inheritance to distribute behavior between classes

Behavioral object patterns use object composition rather than inheritance; some describe how a group of peer objects cooperate to perform a tasks no single object can carry out by itself; others are concerned with encapsulating behavior in an object and delegating request to it

Behavioral Design Behavioral Design PatternsPatterns

Design Pattern Name

Design Purpose Satisfied by this

Pattern

Summary of the Design Pattern

Chain of Responsibility

Command

Interpreter / Iterator

Mediator

Observer

State

Strategy

Visitor

Memento

The Elements of a Design The Elements of a Design PatternPattern

Thank you Thank you