Design Patterns Java™ Workbook

Singleton (Chapter 8)

SOLUTION 8.1

To prevent other developers from instantiating your class, create a single constructor with private visibility. Note that if you create other, nonprivate constructors or create no constructors at all, other developers will likely be able to reinstantiate your class.

SOLUTION 8.2

As Design Patterns says, “You might not have enough information to instantiate every singleton at static initialization time. A singleton might require values that are computed later in the program's execution” (p. 130). When a Factory singleton is born, for example, it might have to establish connections with machine drivers, to set up planners, and to initialize a simulation of itself.

SOLUTION 8.3

Your solution should eliminate the possibility ...