Cisco Cisco Prime Network Services Controller 3.0 Guide Du Développeur
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Filled arrowhead
Indicates a nested flow of control or a procedure call.
Open arrowhead
When used with a solid line, indicates a unidirectional association with the
arrowhead pointing to the known class.
arrowhead pointing to the known class.
Single arrowhead
●
When used with a solid line, indicates inheritance with the arrowhead pointing
to the superclass.
to the superclass.
●
When used with a dashed line, indicates a unidirectional association, in the
direction of the arrowhead.
direction of the arrowhead.
Two or no arrowheads
When used with a solid line, indicates a bidirectional association.
Diamonds
Empty diamond
Indicates a basic aggregation between objects with the empty diamond at the
parent end.
parent end.
Filled diamond
Indicates a composition aggregation between objects with the filled diamond at
the parent end.
the parent end.
Multiplicity Indicators
Indicate the number of instances of the object that can be associated with the connected object.
0..1
Zero or one.
1
Only one.
0..*
Zero or more.
1..*
One or more.
n
Only n, where n > 1.
0..n
Only n, where n > 1.
1..n
Only n, where n > 1.
Inheritance
Similar or closely related classes often use many of the same attributes or methods. To prevent repetitive coding
for multiple classes, UML employs an inheritance mechanism that enables you to reuse existing attributes and
methods.
for multiple classes, UML employs an inheritance mechanism that enables you to reuse existing attributes and
methods.
In an inheritance situation, the class that inherits the information is referred to as the subclass, and the class that is
inherited from is referred to as the superclass. If all attributes and methods of one class are inherited by another
class, that situation is referred to as pure inheritance.
inherited from is referred to as the superclass. If all attributes and methods of one class are inherited by another
class, that situation is referred to as pure inheritance.
In UML diagrams, inheritance is indicated by solid line with a closed arrowhead pointing from the subclass to the
superclass.
superclass.
Aggregations and Compositions
Aggregations and compositions are types of associations that have unique characteristics. When working with UML
diagrams, it is important to understand the differences between aggregations and compositions, and how they are
presented in the diagrams.
diagrams, it is important to understand the differences between aggregations and compositions, and how they are
presented in the diagrams.
Table 6.
Aggregation and Composition Characteristics
In an Aggregation..
In a Composition..
The aggregate object does not affect the
existence of the component object.
That is, if the aggregate object is removed from
the system, the component objects continue to
exist.
existence of the component object.
That is, if the aggregate object is removed from
the system, the component objects continue to
exist.
The aggregate object affects the existence of the component
object.
That is, if the aggregate object is removed from the system,
all component objects are also removed.
object.
That is, if the aggregate object is removed from the system,
all component objects are also removed.
A component object can be aggregated by
other classes in the system.
other classes in the system.
A component object cannot be used by any object other than
its aggregate (or parent) object.
its aggregate (or parent) object.
Changes in the component object can be
propagated to the rest of the system.
propagated to the rest of the system.
Changes in the component object cannot be propagated to
the rest of the system.
the rest of the system.