Change language on Android

Change language on Android

I use below code to change language:
res.getConfiguration().locale = Locale.TRADITIONAL_CHINESE;
It works.
But according to here.
Some language not exist, such as Portuguese, Russian, Spanish, it cannot
be set by this Locale.TRADITIONAL_CHINESE.
I mean Locale. not contains these language, but not that after set not work.
How can I set these language.