Java Singleton vs static - is there a real performance benefit?

Question

I am merging a CVS branch and one of the larger changes is the replacement wherever it occurs of a Singleton pattern with abstract classes that have a static initialisation bloc

Answer 1

From my experience, the only thing that matters is which one is easier to mock in unit tests. I always felt Singleton is easier and natural to mock out. If your organization lets you use JMockit, it doesn't matter since you can overcome these concerns.