Looks like internationalization is not working properly

[McPringle]

When using a browser set to english locale, Apus still shows the german translation instead of the english one.

[McPringle]

Result of analysis: The default translation file translations.properties is being ignored. If the browser locale has no corresponding translation file, the alphabetically first file will be chosen instead of the default file.

[McPringle]

From the Vaadin documentation:

The initial locale is determined by matching the locales provided by the I18NProvider against the Accept-Language header in the initial response from the client.

If an exact match (i.e., language and country) is found, it’ll be used. Otherwise, it tries to match only on language. If neither is found, the locale is set to the first 'supported' locale from I18NProvider.getProvidedLocales(). If that’s empty, Locale.getDefault() is used.

Either the docs are wrong or there is an error I can't find. Apus uses no own 'I18NProvider', so the 'DefaultI18NProvider' provided by Vaadin v24.3+ is used (Apus is based on Vaadin v24.5.4). English is the default, so the english translations are in the fallback file 'translations.properties'. The browser is set to english. The 'Accept-Language' request header is set to english (proven by server-side logging). I would now expect to see the english translations of the UI.

But Apus (Vaadin) is still delivering the german translations. Maybe because the host is set to Swiss German and Vaadin ignore the browser setting. Because even when I add an Africaans ('translations_af.properties') or Danish ('translations_da.properties') translation for testing, which are alphabetically before the German, Vaadin still delivers the German translations.

My result: Either the documentation of Vaadin is wrong or the 'DefaultI18NProvider' has a bug. Okay, there might be a problem with Apus - but I don't think so because I only have to provide the translation file and nothing else...