Creational Design Patterns for Java

• Simple Factory - It is responsible for generating an instance for the client without exposing the internal logic. Usage Examples: When the creation of the objects involves some logic, it is better to use a dedicated factory rather than to repeat the same code in many places.

• Factory Method - Create objects without specifying the exact class of the object that will be created. Usage Examples: When there is some generic processing in the class, but the subclass is dynamically dedicated at runtime.

• Abstract Factory - Group factories that create objects from related classes without specifying the concrete class. Usage Examples: When there is dependency among the objects, encapsulating the creation logic of the individuals factories group.

• Builder - It is responsible for creating different types of objects Usage Examples: When there are different features of the objects or when creating involves many steps.

• Prototype - Create an object based on another exiting object (clone). Usage Examples: When you need to create an object similar to an existing object.

• Singleton - It is responsible for restricting only one instance of a given object from the determined class. Usage Examples When it is necessary to ensure that there is only one object of a class.

References

Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides (1994) - Design Patterns: Elements of Reusable Object-Oriented Software. United States: Addison-Wesley Professional Computing Series.