Are final static variables thread safe in Java?

Question

I\'ve read around quite a bit but haven\'t found a definitive answer.

I have a class that looks like this:

    public class Foo() {

        private          


        

Answer 1

What is thread-safe? Sure, the initialization of the HashMap is thread-safe in the respect that all Foo's share the same Map instance, and that the Map is guaranteed to be there unless an exception occurs in the static init.

But modifying the contents of the Map is most assuredly not thread safe. Static final means that the Map sharedData can not be switched for another Map. But the contents of the Map is a different question. If a given key is used more than once at the same time you may get concurrency issues.