What are some good uses of the Singleton pattern? Is it ever acceptable? [duplicate]

This question already has answers h开发者_如何学Cere: Closed 11 years ago.

Possible Duplicate:

Singleton: How should it be used

I've read that singletons are bad. For instance, it makes the code hard to test. Are there any acceptable uses of singletons?

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Sometimes you want one and only one connection to a database. Making your connector a singleton ensures that you will not spin up multiple connections.