使用类而不是属性文件或 ListResourceBundles 时 ResourceBundle.getBundle() 的强制语言

Question

If I have properties like this:

• I18N.properties
• I18N_en.properties
• I18N_en_US.properties

I can use ResourceBundle.getBundle(Locale.FRANCE) and it will load the default properties (I18N.properties). This also works if I use ListResourceBundle classes instead of properties.

However if I try to use ResourceBundle classes, the rule seems different, I need to have at least a I18N_xx.class , it will not use the default I18N.class : for instance locale en_CA will load I18N_en.class but locale fr_FR (or Locale.FRANCE ) won't load I18N.class , instead I get:

Can't find bundle for base name I18N, locale fr_FR

Furthermore if I add an I18N.properties file, then the getBundle() will find it...

Is is normal behavior? Am I missing something? The doc seems to hint that this is normal (note that the candidates lists in the examples end on {base name}_{lang} ), but if this is so I don't see the rationale? Why should the base default be a properties file?

Answer 1

OK, so the real answer is, the constructor of my base ResourceBundle class was not public...

However, while investigating this I found another weirdness:

It appears that if it cannot find a resource for the language, instead of going to the base file it tries with the default locale: if my default locale is an English-based locale, say, en_IE then asking for an fr_FR resource yields the en one, and if the default is en_US , fr_FR resources come from the en_US bundle.

In a server, that would be a pain because a server-wide default language wouldn't yield an adequate behavior for all users, but it appears that Java defines a language/country neutral Locale.ROOT static for this purpose.