How to make HttpMessageConverter aware of request locale?
In a Spring MVC 3.1 application, how should I use the request's locale to control string formatting by an HttpMessageConverter?
I have this enum:
Code:
public enum Soil {
SAND("0.35"),
PEAT("0.70");
private Double porosity;
Soil(String porosity) {
this.porosity = new Double(porosity);
}
@NumberFormat(pattern = "0.00")
public Double getPorosity() {
return porosity;
}
}
I also have a controller for accessing soil properties:
Code:
@Controller
@RequestMapping("/soil/*")
public class SoilController {
@RequestMapping(value="{id}/porosity")
public @ResponseBody Double getPorosity(@PathVariable String id) {
Soil soil = Soil.valueOf(id);
return soil.getPorosity();
}
}
As I understand it, by using @RequestBody, Spring converts the returned Double to a response body by using an
HttpMessageConverter. This works fine, but the response string is always formatted using the default locale ('en_US' in this case). For instance, a GET request to /soil/PEAT/porosity will result in a '0.7' being written to the response body.
However, most visitors have 'nl' as their preferred locale, expecting a decimal comma instead of a decimal point. In this case, I'd like the response string to be formatted as '0,7'.
I can add an HttpServletRequest parameter to the handler method's signature to determine the request's locale, but don't know how to pass this information to the HttpMessageConverter - a MappingJacksonHttpMessageConverter in this case (*). I know it is possible to configure the MappingJacksonHttpMessageConverter bean by overriding the defaults in the <mvc:annotation-driven> tag, but how do I make it aware of the request locale?
(*) DEBUG: org.springframework.web.servlet.mvc.method.annotat ion.RequestResponseBodyMethodProcessor - Written [0.7] as "application/json;charset=UTF-8" using [org.springframework.http.converter.json.MappingJac ksonHttpMessageConverter@145240a]
