UML Diagrams

2005-02-19T08:37:00.000-08:00

Use Case Diagram

Class Diagram

Sequence Diagram

Object Diagram

Deployment Diagram

Component Diagram

Collaboration Diagram

Activity Diagram

State Diagram

Week 3 Terms

2005-01-29T08:36:00.000-08:00

Abstraction
Abstraction means to filter out an object’s properties and operations until just the ones you need are left. With object-oriented programming, programmers focus on the commonalities among objects in the system, rather than on the special cases.

Inheritance
A form of software reuse in which classes are created by absorbing an existing class’s data and methods and embellishing them with new or modified capabilities.

Polymorphism
Create programs that are often clearer, easier to maintain and easier to extend than programs using switch logic. This is also when an operation has the same name in different classes.

Encapsulation
Encapsulation is when the objects hide the inner workings of their operations from the outside world and from other objects.

Association
Is when objects are related to one another in some way or another.

Multiplicity
Multiplicity is the number of objects of one class that can relate to one object of an associated class.

Qualified Association
Qualified Association is when the multiplicity is a one to many. When an object from one class has to choose a particular object of another in order to fulfill a role in an association, the first class has to rely on a specific attribute to find the right object. That attribute is typically an identifier, such as an ID number. When you make a reservation at a hotel, for instance, the hotel assigns you a confirmation number. If you call with questions about the reservation, you have to supply the confirmation number.

Reflexive Association
When, a class is in an association with itself.

Inheritance & Generalization
The extends keyword in Java declares inheritance of both interface and implementation. UML has an equivalent generalization relationship that is drawn as a solid line with a closed arrowhead from the subclass to the superclass. The additional Sale class helps illustrate the difference between the type of arrowhead used in the UML generalization relationships and those used in directed UML association relationships. Another difference is that, unlike associations, generalization relationships have no need for multiplicities or role names at the ends of the relationship.

Aggregations
One form of aggregation involves a strong relationship between an aggregate object and its component objects. This is called composition. The key to composition is that the component exists as a component only within the composite object. For example, a shirt is a composite of a body, a collar, sleeves, buttons, buttonholes, and cuffs. Do away with the shirt and the collar becomes useless.

Sometimes, a component in a composite doesn’t last as long as the composite itself. The leaves on a tree can die out before the tree does. If you destroy the tree, the leaves also die.

Composites
A composite is a strong type of aggregation. Each component in a composite can belong to just one whole.

Contexts

Interfaces and Realizations
An interface is a set of operations that specifies some aspect of a class behaviour, and it's a set of operations a class presents to other classes. The relationship between a class and an interface is called realization. This relationship is modeled as a dashed line with a large open triangle adjoining and pointing to the interface.

Use Case Diagrams
Use case diagrams model the functionality of system using actors and use cases.

Class Diagrams
Class diagrams are the backbone of almost every object oriented method, including UML. They describe the static structure of a system.

Object Diagrams
Object diagrams describe the static structure of a system at a particular time. They can be used to test class diagrams for accuracy.

State Diagrams
Statechart diagrams describe the dynamic behavior of a system in response to external stimuli. Statechart diagrams are especially useful in modeling reactive objects whose states are triggered by specific events.

Sequence Diagrams
Sequence diagrams describe interactions among classes in terms of an exchange of messages over time.

Activity Diagrams
Activity diagrams illustrate the dynamic nature of a system by modeling the flow of control from activity to activity. An activity represents an operation on some class in the system that results in a change in the state of the system. Typically, activity diagrams are used to model workflow or business processes and internal operation.

Collaboration Diagrams
Collaboration diagrams represent interactions between objects as a series of sequenced messages. Collaboration diagrams describe both the static structure and the dynamic behavior of a system.

Component Diagrams
Component diagrams describe the organization of physical software components, including source code, run-time (binary) code, and executables.

Deployment Diagrams
Deployment diagrams depict the physical resources in a system, including nodes, components, and connections.

Holly Thomas

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UML Diagrams

Week 3 Terms