Getting the client locale in a jersey request

The client should set the Accept-Language header.

Locale locale = request.getLocale();

Use the HTTP Header for that. To request the numeric value in the US Locale decimal you can request like that:

GET /metrics/007/size Accept-Language: en-US

Then from the code:

public Response myRequest(@Context HttpServletRequest request) {
Locale locale = request.getLocale();
...
}