The Singleton design pattern provides a solution:
Hide the constructor of a class, and define a static operation (getInstance())
that returns the sole instance of the class.
Describing the Singleton design in more detail is the theme of the following sections. See Applicability section for all problems Singleton can solve.

• The key idea in this pattern is to make a class itself responsible that it can be instantiated only once.
• Hide the constructor of a class.
  Declaring the constructor of a class private ensures that the class can neither be instantiated (from outside the class) nor subclassed (because subclasses need the constructor of their parent class).
  "Enforce the singleton property with a private constructor or enum type" [JB08, Item 3]
• Define a static operation (getInstance()) that returns the sole instance of the class.
  getInstance() is declared public and static.
  A public static operation of a class is easy to access from anywhere within an application by using the class name and operation name (= global point of access): Singleton.getInstance().