1. Unified Modeling Language (UML)

2. UML Graphic modeling language for describing object-oriented software.
Started in 1994
Combined notations from 3 leading OO methods
OMT, Object-modeling technique (James Rumbaugh)
OOSE, Object-oriented software engineering (Ivar Jacobson)
Booch method (Grady Booch)

3. Core UML Diagrams
A diagram is the graphical presentation of a set of elements, most often rendered as a connected graph of things and relationships.
Use case diagrams
Describe functional behavior seen by (external) users
Class diagrams
Describe static structure of the classes in system

4. Use case diagrams
Use Case Diagrams describe the functionality of a system and users of the system, i.e. what a new system should do or what an existing system already does. These diagrams contain the following elements:
Actors, which represent users of a system, including human users and other systems.
Use Cases, which represent functionality or services provided by a system to users.
System boundary
Association
Actor (People)
Actor (Systems)
Use Case
System

5. An use-cases example Library Supplier Borrow books Return books
Interlibrary loan
Circulation Clerk
Do research
Read books, newspaper
Member
Purchase supplies
Supplier

6. Class diagrams
The class diagram is the main building block in object oriented modeling. It
represents the static structure of a system,
describes how a system is structured rather than how a system behaves.
contains the following elements:
Classes, which represent entities with common characteristics or features. These features include attributes and operations.
Associations, which represent relationships between classes.

7. Basic UML notation for classes
Class name
Class name
attribute:primitiveDataType or Class
attribute: type or Class=default value
method ( )
method (argument_list):type or Class
Attribute visibility
- (private)
# (protected)
+ (public)
~(package)
Operations
- (private)
# (protected)
+ (public)
Basic UML notation for classes

8. Basic UML notation for classes
Example
Basic UML notation for classes
Class name
Transcript
+studentName: String
+studentID: int
+listOfCourseNames: List=null
+lilstOfGrades:List=null
+GPA: int
+setStudentName(String name)
+setStudentID(int ID)
+addCourseName(String course)
+addGrade(Char grade)
+calculateAverage(): int
+show()
Attribute
Operations

9. Parameterized classes
type
Stack
+pop() : <type>

10. Basic Class Relationships
Class A
Class with
parts
Class with
parts
Class A
Superclass
Interface
name
Class B
Assembly
Class
Assembly
Class
Class B
Subclass
Concrete
Class
Association
Aggregation
Composition
Inheritance
(Generalization)
Dependency
Realization

11. Associations A link between two classes
Typically modeled as a member reference
A Person works for a Company
multiplicity
Role names
employee
employer
Person
Company
0..* 1
works for
Association Name
Role names and multiplicity at association ends
Direction arrow to aid reading of association name

12. Recursive Association
Person
Node
Connects
married to

13. Aggregation
A special form of association that models a whole-part relationship between an aggregate (the whole) and its parts.
Models a “is a part-part of” relationship.
multiplicity 4
Car
Wheel
wheels
Whole
Part

14. Composition A strong form of aggregation
The whole is the sole owner of its part
The part object may belong to only one whole
Multiplicity on the whole side must be one
The life time of the part is dependent upon the whole
The composite must manage the creation and destruction of its parts
multiplicity
Line
Point
3..* 2
Polygon

15. Dependency
A dependency indicates a semantic relation between two or more classes in which a change in one may force changes in the other although there is no explicit association between them
A stereotype may be used to denote the type of the dependency
Iterator
Vector

16. Generalization
Indicates that objects of the specialized class (subclass) are substitutable for objects of the generalized class (super-class)
“is a” relationship
Shape
Super Class
May be an abstract class
Generalization relationship
Sub Class
Circle

17. Generalization conti. A sub-class inherits from its super-class
Attributes
Operations
Relationships
A sub-class may
Add attributes and operations
Add relationships
Refine (override) inherited operations

18. <<interface>> List
Realization
A realization relationship indicates that one class implements a behavior specified by another class (an interface or abstract class).
An interface can be realized by many classes.
A class may realize many interfaces.
LinkedList
<<interface>> List
LinkedList
List

19. Basic Class Diagram (Example)
Person
Head
Arm
Class
Student
takes

20. Example: Class Diagram
Student
Transcript
Course *
Transcript
studentName
studentID
listOfCourseNames
lilstOfGrades
average
setStudentName()
setStudentID()
addCourseName()
addGrade()
calculateAverage()
show()
Student
studentName
studentID
listOfCoursesID
transcript:Transcript
setStudentName()
getStudentName()
setStudentID()
getStudentID()
addToListofCourseIDs()
makeTranscript()
Course
courseName
courseID
grade
readCourseData()
readCourseGrade()
setCourseID()

21. UML Class Diagrams  Java Code
Different representations of the same information
Name, state, behavior of class
Relationship(s) between classes
Should be able to derive one from the other
Motivation
UML  Java
Implement code based on design written in UML
Java  UML
Create UML to document design of existing code

22. Java  UML: Clock Example
Java class Clock // name { // fields, members int seconds; int minutes; int hours; // methods void start(); void adjustTime(); void reset(); }
Name
Attributes
Operations
Class diagram
Java code

23. Two basic relationships of Java classes
class A { …. }
class B {
A x = new A(); … }
Class B has-a class A.
class A { …. }
class B extends/implements A { … }
Class B is-a class A.
Relationships association, aggregation and dependency are has-a relationships.
Generalization and realization are is-a relationships.

24. UML Packages A package is a general purpose grouping mechanism.
Can be used to group any UML element (e.g. use case, actors, classes, components and other packages.
Commonly used for specifying the logical distribution of classes.
Name

25. Packages and Class Diagrams
Add package information to class diagrams b a
b.a
a.A
b.b.D
b.b.E
b.a.F
b.a.G
a.C
a.B
b.b

26. Homework A B C D E F In the following questions fill in is-a or has-a.
Class D ______ class A.
Class D ______ class E.
Class E ______ class B.
Class E ______ class C.
Class F ______ class E.