Relationships

In Unified Modeling Language (UML) visualization class diagrams, a relationship is the connection between Java classes or interfaces or between Enterprise JavaBeans (EJB) enterprise beans.

You can use several relationships to define the structure between Java classes or interfaces or between enterprise beans:

• Association relationships imply that instances of one class connect to instances of another class.

• Dependency relationships imply that a change to one class might affect another class.

• Extends relationships imply that one class is a specialization of another class.

• Implements relationships imply that one class provides a specification and the other class implements the specification.

You can also use note attachment relationships to provide additional information about diagram elements.

Association relationships
In Unified Modeling Language (UML) visualization class diagrams, an association is a structural relationship that indicates that objects of one classifier (such as a class and interface) are connected and can navigate to objects of another classifier.

Dependency relationships
In Unified Modeling Language (UML) visualization class diagrams, a dependency relationship indicates that a change to one class (the supplier) might cause a change in the other class (the client). The supplier is independent because a change in the consumer does not affect the supplier.

Extends relationships
In Unified Modeling Language (UML) visualization class diagrams, an extends relationship (also called an inheritance or an is-a relationship) implies that a specialized (child) class is based on a general (parent) class.

Implements relationships
In Unified Modeling Language (UML) visualization class diagrams, an implements relationship exists between two classes when one of them must implement, or realize, the behavior specified by the other.

Owned element association relationships
In Unified Modeling Language (UML) visualization class diagrams, an owned element association relationship is a type of association that dictates ownership.

 

Parent topic

About UML class diagrams

 

Related concepts

Class diagrams
Class shapes
Classifiers
Classes
Attributes
Operations
Adornments for unresolved references
Multiplicity
Visibility