Class Diagram Associations Class Diagrams, Class Stereotypes, Class Associations Dr. Neal CIS 480

Class Diagram Provides definition of system components Contains important structural information for the new system Provides details describing database and object-oriented program Consists of problem domain classes and implementation classes Provides a static view of the system

UML Class Representation Rational

Class Stereotypes and Views Icon representation Label representation Same class different view

Bank Account Class Associations Navigable association Inheritance association

Unidirectional and Navigable Associations Unidirectional Customer knows about Order, but Order doesn’t know of customer Bidirectional or Navigable Customer knows about Order and Order knows about Customer

Class to Class Messages public class Order { // some attributes protected String customerName; protected Customer CustomerOwner; // some methods public setCustomerName(String name) { customerName = name; } public class Customer { // some attributes protected String name; protected Order[] OrderList; // some methods private void doName() { OrderList = new Order[2]; OrderList[0] = new Order(); OrderList[0].setCustomerName(name); } Array of Order objects Call or message to Order object

A Generalization/Specialization Hierarchy for Motor Vehicles

Class Specialization public class Consumer : Customer { // some attributes // some methods } public class Customer { // some attributes protected String name; // some methods private void doName() { // do something } public class Commercial : Customer { // some attributes // some methods } Colon key word for subclass Superclass Subclasses

Aggregation or Whole-Part Relationships

Class Aggregation public class Engine { // some attributes // some methods } public class Car { // some attributes protected Wheel[] WheelList; protected Engine ClassEngineOject; // some methods } public class Wheel { // some attributes // some methods } Object collection for wheels and single id for engine Aggregate class Parts classes

Enrollment Class Diagram with Association Class

Association Class public class Product { // some attributes protected Vendor[] VendorList; // some methods } public class Shipment { // some attributes public Vendor VendorObject; public Product ProductObject // some methods } public class Vendor { // some attributes protected Product[] ProductList; // some methods } Association class Other classes

Multiple Inheritance by Interfaces Sometimes a class needs to provide behavior matching more than one class If the class is already of subclass of another base class then inheritance can’t be used so how is this additional behavior guarantee We need a relationship that establishes a contract for one class to implement another's behavior The behavior can be defined with an Interface The “Realizes” relationship forces the interface to be implemented by the class In this way a class may “Realize” the behavior of multiple classes

Multiple Inheritance the Realizes Relationship public interface MessageInterface { // some method signatures Boolean receiveMessage(String msg); } public class Window { // some attributes // some methods } public class ListBoxControl : Window, MessageInterface { // some attributes // some methods Boolean receiveMessage(String msg) { // do something } ListBoxControl has a contract to implement methods Base class Sub class Contract or Interface class Multiple Inheritance using an Interface

Partial Domain (static) Class Diagram for RMO