The keyword for that is
NLS or - sometimes also used
i18N. Sometimes it's even called
internationalization or
multi language support.
Java uses UTF-8 for the GUI, looking at this tutorial:
JSF 2 Internationalization Example[
^]
...I expect the JSF Components to do the same.
I strongly recommend using the RBE-Plugin in Eclipse, that one helps organizing the language files and converts all non-conform Characters into UTF-8:
Eclipse ResourceBundle Editor[
^]