Creating a static reference versus a singleton

Question

I am using the java driver for mongodb, and the documentation says to:

"you should create a single Mongo instance, and you can use it in every request."

Using a single instance sounds like a singleton.

In other places for a different library I have read the instructions saying that I should create a static reference as it is thread-safe.

Can someone explain the differences between a singleton and creating a static reference?

So the actual code that I need to instantiate either statically or via a singleton would be:

Mongo m = new Mongo( "localhost" , 27017 );

Can someone explain both methods and the underlying differences if any?

Answer 1

In Java you typically use a static variable to implement the Singleton pattern.

http://java.sun.com/developer/technicalArticles/Programming/singletons/