Singleton Design Pattern, UML diagram, Java Example
Definition
Ensure a class only has one instance, and provide a global point of access to it.
Class Diagram
Participants
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Singleton.
- defines an Instance operation that lets clients access its unique instance.
- responsible for creating and maintaining its own unique instance.
Benefits
- Controlled access to unique instance.
- Reduced name space.
- Allows refinement of operations and representations.
- Permits a variable number of instances.
- More flexible than class operations.
Usage
- When there must be only one instance of a class.
