REFERENCE UML CARD
1998 Allen I. Holub. All Rights Reserved.
Available from <http://www.holub.com>.
E.g.: Some_class abstract { author: George Jetson modified: 10/6/2999 checked_out: y } Guillemets identify stereotypes. E.g.: static, abstract JavaBean. Can use graphic instead of word. Access privileges (see below) can precede name. Inner (nested) classes identify outer class as prefix of class name: (Outer.Inner or Outer::Inner). 2. The attributes compartment (optional): During Analysis: identify the attributes (i.e. defining characteristics) of the object. During Design: identify a relationship to a stock class. This:
Person String name;
Associations (relationships between classes) A
1..* relationship 1..* A's role in B B's role in A
Implementation Inheritance
SuperClass
B
Static Model Diagrams
Packages
Associated classes are connected by lines. The relationship is identified, if necessary, with a < or > to indicate direction (or use solid arrowheads). The role that a class plays in the relationship is identified on that class's side of the line. Stereotypes (like friend) are appropriate. Unidirectional message flow can be indicated by an arrow (but is implicit in situations where there is only one role):
Sender Receiver
- void concrete(); + int override();
SubClass + int override(); + int additional();
Outline arrows identify derivation relationships: extends, implements, is-a, has-properties-of, etc. Variations include:
com.hulub
Java.awt
Cardinality: 1 n 0..1 1..* * Example:
Company give_me_a_raise(Employee e)
Usually omitted if 1:1 Unknown at compile time, but bound. (1..2 1..n) 1 or more 0 or more Interface Inheritance
User f() { x.operation() }
Application Tools
Oracle
Database Interfaces
is a more compact (and less informative) version of this:
Person String
Sybase
relationship
x Implementer Employee Iface Name
C++ namespace. Group together functionally-similar classes. Derived classes need not be in the same package. Packages can nest. Outer packages are sometimes called domains. (In the diagram, "Tools" is arguably an outer package, not a domain). Package name is part of the class name (e.g. given the class fred in the flintstone package, the fully-qualified class name is flintstone.fred). Generally needed when entire static-model won't fit on one sheet.
name
Everything, here, is private. Always. Period. 3. The operations compartment (optional) contains method definitions. Use implementation-language syntax, except for access privileges: + public # protected - private ~ package (my extension to UML) Abstract operations (C++ virtual, Java non-final) indicated by italics (or underline). Boldface operation names are easier to read. If attributes and operations are both omitted, a more complete definition is assumed to be on another sheet.
1 1
operation()
boss 1
operation()
1 <works for employer
1..n you_re_fired() peon 1..* flunkies
class Company { private Employee[] peon = new Employee[n]; public void give_me_a_raise( Employee e ) { ... } } class Employee { private Company private Employee private Vector public void }
In C++, an interface is a class containing nothing but pure virtual methods. Java supports them directly (c.f. "abstract class," which can contain method and field definitions in addition to the abstract declarations.) My extension to UML: rounded corners identify interfaces. If the full interface specification is in some other diagram, I use:
Implementer Name User
Classes (Box contains three compartments)
Class name Attributes:
employer; boss; flunkies = new Vector(); you_re_fired() { ... }
Strict UML uses the interface stereotype in the name compartment of a standard class box:
InterfaceName
Operations:
(A Java Vector is a variable-length array. In this case it will hold Employee objects)
interface
Operations
1. The name compartment (required) contains the class name and other documentation-related information:
Java, defaults unfortunately, to "package" access when no modifier is present. In my "flavor" of UML, a missing access privilege means "public".
Interfaces contain no attributes, so the attribute compartment is always empty.
Aggregation (comprises)
Whole Part
In official UML, put arbitrary constraints that affect more than one relationship in a "comment" box, as shown. I usually leave out the box. Qualified Association
User add(String key, Item value) key bag Item
Destroying the "whole" does not destroy the parts. Cardinality is allowed. Composition (has) relationship
Container role Item
Top boxes represent objects, not classes. You may optionally add ":class" to the name if desired. Vertical lines represent the objects "life line", or existence. Broken lifeline indicates the object is inactive, a rectangle indicates the object is active. represent messages being sent. (optional if synchronous) represent method return. (May label arrow with name/type of returned object). Sending object's class must have: 1. An association of some sort with the receiving objects class. 2. The receiver-side class's "role" must be the same as the name of the receiving object. Object Creation
Sender
Loops (extension to UML)
Sender do_it() message() Every Receiver
Hash tables, associative arrays, etc.
class User { // A Hashtable is an associative array, indexed // by some key and containing some value. private Hashtable bag = new HashTable(); private void add(String key, Item value) { bag.put(key, value); } }
The parts are destroyed along with the whole. Doesn't really exist in Java. In C++:
class Container { Obj item1; Obj *item2; public: Whole() { item2 = new Obj; } ~Whole(){ delete item2; } };
Don't think loops, think what the loop is accomplishing. Typically, you need to send some set of messages to every element in some collection. Do this with every. You can get more elaborate (every receiver where x<y) The diagram above comes from:
sender_class 1 void do_it() sender receiver n void message() receiver_class
and maps to the following code:
class sender_class { receiver_class receiver[n]; public do_it() { for(int i = 0; i < n; ++i) receiver[i].message(); } }
Association Class
Airline
Constraint
{ordered} Container role Identity key() Item
<travels on Person carr...