Elegant way to get Locale in Spring Controller

yetimoner picture yetimoner · Oct 10, 2015 · Viewed 15.5k times · Source

I'm looking for a cleaner way (in Spring 3.2) to get the current locale than explicitly calling LocaleContextHolder.getLocale() at the start of each Controller method. It has to be compatible with Java annotation, as I'm not using the XML config. Here's what I'm doing currently.

@Controller
public class WifeController {
    @Autowired
    private MessageSource msgSrc;

    @RequestMapping(value = "/wife/mood")
    public String readWife(Model model, @RequestParam("whatImDoing") String iAm) {
        Locale loc = LocaleContextHolder.getLocale();
        if(iAm.equals("playingXbox")) {
            model.addAttribute( "statusTitle", msgSrc.getMessage("mood.angry", null, loc) );
            model.addAttribute( "statusDetail", msgSrc.getMessage("mood.angry.xboxdiatribe", null, loc) );
        }
        return "moodResult";
    }
}

Answer

fps picture fps · Oct 10, 2015

In Spring 3.2 reference docs, section 17.3.3, Supported method argument types:

The following are the supported method arguments:

  • Request or response objects (Servlet API). Choose any specific request or response type, for example ServletRequest or HttpServletRequest.

    (...)

  • java.util.Locale for the current request locale, determined by the most specific locale resolver available, in effect, the configured LocaleResolver in a Servlet environment.

So all you'd need to do is receive an instance of Locale as an argument in every method:

@RequestMapping(value = "/wife/mood")
public String readWife(Model model, @RequestParam("whatImDoing") String iAm, Locale loc) {
    if (iAm.equals("playingXbox")) {
        model.addAttribute("statusTitle", msgSrc.getMessage("mood.angry", null, loc));
        model.addAttribute("statusDetail", msgSrc.getMessage("mood.angry.xboxdiatribe", null, loc));
    }
    return "moodResult";
}