In issue NMS-5426, Benjamin created a fix to better handle locale in HTTP data collection.
His fix tries to parse the HTTP data with the following locale (in order):
1- The HTTP response's locale
2- OpenNMS' system locale
However his patch isn't quite correct; To devise the HTTP response's locale, he uses the getLocale() method which is only intended to be used by the server when generating a HTTP response.
After some research, it seems that the only way to devise an HTTP response's locale is by looking for a "Content-Language" HTTP header (RFC2616).... Well, it's also possible to have locale information in <meta> tags, but let's keep that out of the discussion for now...
I've written a small patch to let HttpCollector do this if you like.