UML - Basic Notations
Every UML diagram belongs to one these two diagram categories. . However, in C++ and Java, all parameters are "in" parameters and In Figure 4, the inheritance relationship is drawn with separate lines for . use multiple topic- specific class diagrams instead of just producing one large class diagram. An "association" in UML is defined as a kind of relationship between instance across the given association, in other words, how many objects of one class (the notation, the symbol (*) stands for "many" (unbounded number), and the. UML Class Diagrams Reference - class, classifier, association, aggregation, composition. A visibility keyword or symbol in this case can be given once for multiple Note, that UML's "anchor" notation is still used in one example in UML x . Qualifiers are used to model hash maps in Java, dictionaries in C#, index.
Figure 11 shows an association class for our airline industry example.
UML - Basic Notations
Adding the association class MileageCredit View image at full size In the class diagram shown in Figure 11, the association between the Flight class and the FrequentFlyer class results in an association class called MileageCredit. This means that when an instance of a Flight class is associated with an instance of a FrequentFlyer class, there will also be an instance of a MileageCredit class.
Aggregation Aggregation is a special type of association used to model a "whole to its parts" relationship. In basic aggregation relationships, the lifecycle of a part class is independent from the whole class's lifecycle.
For example, we can think of Car as a whole entity and Car Wheel as part of the overall Car. The wheel can be created weeks ahead of time, and it can sit in a warehouse before being placed on a car during assembly. In this example, the Wheel class's instance clearly lives independently of the Car class's instance. However, there are times when the part class's lifecycle is not independent from that of the whole class — this is called composition aggregation.
UML Class Diagrams - Graphical Notation Reference
Consider, for example, the relationship of a company to its departments. Both Company and Departments are modeled as classes, and a department cannot exist before a company exists. Here the Department class's instance is dependent upon the existence of the Company class's instance. Let's explore basic aggregation and composition aggregation further. Basic aggregation An association with an aggregation relationship indicates that one class is a part of another class.
In an aggregation relationship, the child class instance can outlive its parent class. To represent an aggregation relationship, you draw a solid line from the parent class to the part class, and draw an unfilled diamond shape on the parent class's association end.
Figure 12 shows an example of an aggregation relationship between a Car and a Wheel. Example of an aggregation association View image at full size Composition aggregation The composition aggregation relationship is just another form of the aggregation relationship, but the child class's instance lifecycle is dependent on the parent class's instance lifecycle.
In Figure 13, which shows a composition relationship between a Company class and a Department class, notice that the composition relationship is drawn like the aggregation relationship, but this time the diamond shape is filled.
Objects can be anything having properties and responsibility. Object Notation The object is represented in the same way as the class.
The only difference is the name which is underlined as shown in the following figure. As the object is an actual implementation of a class, which is known as the instance of a class.
The class diagram
Hence, it has the same usage as the class. Interface Notation Interface is represented by a circle as shown in the following figure. It has a name which is generally written below the circle. Interface is used to describe the functionality without implementation. Interface is just like a template where you define different functions, not the implementation.
When a class implements the interface, it also implements the functionality as per requirement. Collaboration Notation Collaboration is represented by a dotted eclipse as shown in the following figure.UML Tutorial 3.2 - Basics of Association relationships in a Java Class Diagram with Papyrus
It has a name written inside the eclipse. Generally, responsibilities are in a group. Use Case Notation Use case is represented as an eclipse with a name inside it. It may contain additional responsibilities.
Use case is used to capture high level functionalities of a system. Actor Notation An actor can be defined as some internal or external entity that interacts with the system. An actor is used in a use case diagram to describe the internal or external entities. Operations getName and listFiles either have no parameters or parameters were suppressed.
Signature of the operation has optional parameter list and return specification. Parameter-list is a list of parameters of the operation in the following format: Type-expression is an expression that specifies the type of the parameter. Multiplicity is the multiplicity of the parameter. Default is an expression that defines the value specification for the default value of the parameter.
Design Codes: UML Class Diagram: Association, Aggregation and Composition
Parameter list can be suppressed. Operation setDaemon has one input parameter, while single parameter of changeName is both input and output parameter. Static enumerate returns integer result while also having output parameter - array of threads.
Operation isDaemon is shown with return type parameter. It is presentation option equivalent to returning operation result as: Direction of parameter is described as one of: Optional parm-properties describe additional property values that apply to the parameter. Return specification also has optional multiplicity of the return type. Operation check redefines inherited operation status from the superclass. Operation getPublicKey does not change the state of the system.