How to get user locale

Is there any method to get the user locale?

I found that there's a method getDefault(), but it seems get the system locale, but not the user locale.

Any ideas? Thanks!

By reading variables like user.language, user.country and user.variant ?

So for example you have a Japanese person sitting at a computer in the United States, and you want to find out that the person is Japanese? No? Then what is the difference in your mind between the "user" locale and the "system" locale?