Configuration conf = getResources().getConfiguration();
conf.locale = new Locale("es") // Deprecated
String language = conf.locale.getDisplayName() //Deprecated

Locale locale;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
    locale = context.getResources().getConfiguration().getLocales().get(0);
} else {
    locale = context.getResources().getConfiguration().locale;
}

Configuration conf = getResources().getConfiguration();
conf.setLocale = new Locale("es") // VERSION_CODES.JELLY_BEAN_MR1+
String language = conf.getLocales().get(0).toString() // VERSION_CODES.N+

Configuration config = context.getResources().getConfiguration();

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
     locale = getSystemLocale(config);
} else {
     locale = getSystemLocaleLegacy(config);
}

Locale locale = new Locale("es");
Locale.setDefault(locale);

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
     setSystemLocale(config, locale);
} else {
     setSystemLocaleLegacy(config, locale);
}