Sun Java Studio 8 supports the following locales by default: English, Japanese and Simplified Chinese. The ide should automatically default to the current locale.
You can also force the ide to use a different locale than the current locale. Use the following startup switch on the command line or add it to the netbeans.conf file
-locale zh
http://www.netbeans.org/kb/41/using-netbeans/configuring.html#switches