About this kata
This kata refers to the book Effective Java by Joshua Bloch.
It addresses
Item 1: Consider static factory methods instead of constructors.
Problem description
Provid a class that
Use factory method to construct an instance by a good understandable name.
The instance shall be only created when there is no existing one.
advantages of factory method usage instead of constructors:
Unlike constructors the method has a meaningful name.
Unlike constructors it is not required to create a new object each time they are invoked.
Unlike constructors it can return an object of any subtype of their return type.
The returned object can vary from call to call as function of the input parameters.
The class of the returned object need not exist when the class containing the method is written. ????
Clues