UML Class Diagrams

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UML Class Diagrams

• CS2335
• Spring 2005

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Miscellaneous

• Drawing Software
• Dia
• Visio, Argo, Poseidon
• Rational Rose
• From csh in Baird cluster type
• source /usr/local/rational/rs_setup.csh
• Rose
• QSEE SuperLite
• Omondo (http//www.omondo.com/)
• Hand-drawn and then scanned

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Agenda

• Package Diagrams
• Class Diagrams
• Symbology
• Basic Modeling
• Intermediate Modeling

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Package Diagrams

• Show basic package structure
• represents packages or namespaces
• Each classname in a package must be unique
• Show dependencies between packages
• Something in a package uses something in another
  package
• Typically a class in one package calls methods in
  another class.

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Packages
A dependency
ServerServer
A Fully-Qualified Name
A package
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Simple Package Diagram
Well-structured is acyclic
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A Package Diagram
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Lab 5 Package Diagram
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Class Diagrams

• A class diagram shows
• Packages (sub-packages of our package diagram)
• Classes
• Attributes
• Methods
• Interfaces
• Collaborations
• Dependency, Generalization, Relationships
• A class diagram is a STATIC view of system

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Three Levels of Class Diagrams

• Conceptual (Domain) Model
• Analysis (Specification)
• Implementation

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Basic Class Diagrams
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Basic Class Diagrams
public protected - private package /
derived
Abstract abstract
constructor query update
Class Scope (static)
Formats for boxes Visibility Attribute_Name
MultiplicityType Initial_Value
property-string Visibility Method_Name
(Parameter_List) Return-List property-string K
ind param_Name type default value
where kind in, out , inout
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Basic Class Diagrams
Superclass
Class with parts
Note
Assembly Class
Subclass
Composition (Aggregation) (part-of, has-a)
Association (relationship)
Inheritance (Generalization) (is-a, kind-of)
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Basic Class Diagram (Example)
takes
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Basic Class Diagram (Example)
Person
name String - ssn String birthday
Date / age int
getName String query -calculateAge int
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Class Diagrams (Advanced)
Cardinality (Multiplicity) 1 0..1 0.. 1..
64 2..5 2,4,10
takes
0..
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Class Diagrams (Advanced)
Important Stereotypes ltltinterfacegtgt specify
collection of operations to specify
services ltlttypegtgt specify structure and
behavior (not implementation) ltltenumerationgtgt
specify discrete values ltltimplementationClassgtgt
helper class created in detail design
ltltenumerationgtgt Status
Idle Working Error
Fundamental Attributes
readImage writeImage
Fundamental behavior
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Class Diagrams (Advanced)
Aggregation (independent object lifetime)
Composite (unique member, dependent)
Can have self-associations
Exception handling
ltltsendsgtgt
manager
manages
employee
directionality
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Class Diagrams (Advanced)
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From Domain to Analysis (Specification)
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From Analysis (Specification) to Implementation
Book
Author
-isbnstring -titlestring
written by
-namestring

1..5
Book
Author
-isbnstring -titlestring writtenby5 Author
-namestring
- writtenby ListltBookgt
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From Implementation to Code
Author
public class Author private String name
private List writtenby public class Book
private String isbn private String title
Author writtenby5
-namestring
- writtenby ListltBookgt
Book
-isbnstring -titlestring writtenby5 Author
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One Additional Class Box
Class with independent Runtime thread of execution
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Class Diagram Hints

• Provide abstraction of problem domain
• Embodies small set of well-defined
  responsibilities
• Clear separation between specification and
  implementation
• Understandable and simple
• Show only important properties

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Class Diagram Hints

• Organize similar classes into packages
• Beware of cyclical generalization/dependencies
• Use associations where there are structural
  relationships
• Associations are NOT comm pipes!!!!!!!
• Start with Conceptual model, then refine details
  thru specification and implementation

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Design Digression

• Inheritance vs. Composition
• Information Hiding
• Delegation Design Pattern
• Inheritance vs. Attribute
• Attribute vs. Class
• Association Checklist (page 155)
• Class Identification (page 139)
• Domain analysis
• Nouns in requirements
• Data-driven vs. Responsibility-driven
• Proxy Classes

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Lab 5 Class Diagram