Static Class Structure

• Singleton
  • (1) Defines an INSTANCE constant of type Singleton that holds the sole instance of the class.
  • Fields declared final are initialized once and can never be changed.
  • (2) Hides its constructor (private Singleton() {}).
  • This ensures that the class can never be instantiated from outside the class.
  • (3) Defines a static operation (getInstance()) for returning the sole instance of the class.