Singleton Considered Stupid

Steve writes this in 2004 with the frustration of an Amazon interviewer who has heard one too many candidates name "Singleton" as the design pattern they know. He opens with the Simpleton Pattern: the candidate who claims to have read GoF and can only name the Singleton and possibly "the Visitater." Then comes the confession — Steve loved Singleton, built fifty Manager classes around it, wrote his own boilerplate-reduction delegation layer, and emailed Ralph Johnson to ask if static methods still counted (they do) — and found himself with a Java codebase in which classes were pure namespaces and the entire OO machinery had been swept under a rug. The objections that follow cover memory leaks, resource leaks, the impossibility of subclassing, the brittleness of static methods, the double-checked-locking trap, and the danger of accidental Doubletons under threads. The closer seeds his later essays: about a third of the GoF patterns aren't really OO patterns but workarounds for C++ deficiencies — Visitor is map, Strategy is a first-class function, Iterator is a poor man's Visitor, stateful Strategy is a closure.

The Kingdom-of-Nouns essay two years later is this last paragraph fully grown. The prescription at the end is small and practical: when in doubt, use Factory Method. Computers are fast. Treat yourself to a few extra instances. The reason the piece still gets cited is that the same anti-pattern keeps replaying itself, with the next mis-applied magic tool in the slot where "Singleton" used to be.