UML

a crash courseAlex LoBrian Kiefer

Overview

ClassesClass RelationshipsInterfacesObjectsStatesWorksheet

Classes

Drawn as a three section box: Name Fields Functions

+Operation1()

-Attribute1

Class Name

ClassesFields and functions given visibility signs+ sign indicates public- sign indicates private# sign indicates protected

Fields are shown as name:typeFunctions are shown as Function(argument1:type, …):returnTypeItalic class or method names indicate the class is abstractStatic fields and functions are underlined

Cooper Examplepublic abstract class Person

{

protected String personName;

private int age;

public Person (String name) { personName = name; }

static public String makeJob () {return "hired";}

public int getAge () {return age;}

private void splitNames () { }

abstract String getJob ();

}

Alternate Diagrams

Packages

Packages are depicted as large folders with classes contained inside

Package Name

+Operation1()

-Attribute1

Class Name

+Operation1()

-Attribute1

Class Name Class1

Notes

UML does not require that you show everythingTo draw a note in UML

+Operation1()

-Attribute1

Class Name

This is some sort of note

Class Relationships

Use a solid line with a hollow arrowhead to show a parent class

Class1 Class2

Class2 extends Class1

Cooper Examplepublic class Employee extends Person { public Employee (String name) { super (name); }

public String getJob () { return "Research Staff"; } }

Relationships

A single line often represents that one class contains an instance of anotherUse a diamond to show that one class has a collection of the other classSometimes a small circle is used to show that the instance is singular

Class1 Class2

Class1 Class2

Class1 Class2

Relationship Cardinality

Exactly 1

Many (0 and up)

Optional (0 or 1)

One or moreN to M (not shown)

Class2-N

0..1

-M

1

Class2-N

0..1

-M

*

Class2-N

0..1

-M

0..1

Class2-N

0..1

-M

1..*

Relationships

An open arrow indicates navigability – it shows that one class has a ref to another and the other may not

Class1 Class2

Class1 Class2relationship

relationship

Dependency

A dashed arrow shows a dependency on a class that does not use an object ref Example: using static method of another

classothers?

Class1 Class2

Other Relations

Another relation can be done using the dashed arrows like throwing

Class1 Class2«bind»

(bind can be any keyword, such as throw, send, become, friend, etc)

InterfacesInterfaces are drawn similarly to classes, except without a field area (usually) and the <<interface>> stereotypeAn interface which you don’t need to define can be drawn as a “lollipop”

«interface»InterfaceName RemoteInterface

Interfaces

To show a class implements an interface, use a dashed line with an open arrowhead

Class1 «interface»InterfaceName

Class2

RemoteInterface

Notes on Interfaces

While interfaces and their methods are always abstract in java, their methods do not appear italicized. As opposed to abstract classes and abstract methods.

*This was disagreed on between Cooper and our book.

Objects

You can show an object by giving its name and type separated by a colon (or just either/or) and underlining itA line between objects indicates that one object has a reference to another.

s:String :Char«uses»

Calling Methods from Objects

You can show a sequence of objects calling methods of other objects

The order is from top to bottom

The dashed line indicates the object over time

A bold outline of the box represents the class is running on a separate thread

LinkedList List

addFirst(:Object)

States

UML can also be used to model the various states of a program or method Think Introduction to Logic Design Think events (clicks, key presses, etc.)

Closed

Opening

Open StayOpen

Closing

click

click

click

click

click

complete

completetimeout

Other uses of UML

Collaboration diagramsUse case diagramsActivity diagramsDeployment diagramsEtc.

More Resources

Our book, p 442-447Safari Online:Java™ Design Patterns: A TutorialBy James W. CooperChapter 2

UML Distilled

Message Repository

MailAccountList

MailAccount(POP3, IMAP or

Local)

...

POP3Account

LocalAccount

IMAPAccount

Inherits from

MailAccount

Contains

MailAccount(POP3, IMAP or

Local)

MailboxList

MailBox(POP3/Local or

IMAP)

...

MailBox(POP3/Local or

IMAP)

Mailbox

LocalMailbox(POP3Mailbox)

IMAPMailbox

Inherits from

Contains

MailMessageList

MailMessage(POP3/Local or

IMAP)

...

MailMessage(POP3/Local or

IMAP)

Contains

MailMessage

LocalMailMessage(POP3MaiMessage)

IMAPMailMessage

Inherits from

POP3 Protocol

IMAP Protocol

Internal

Use

Use

Pluggable Universal Multiple Mail Account Structure

Discussion