Spring @RestController获取请求内容类型以响应json或html

如何获取请求的Content-Type值？我们需要它来打印json响应或HTML respone。我的代码是这样的：

 @RestController
public class GestorController {
    @RequestMapping(value="/gestores", method = RequestMethod.GET)  
    public Object gestoresHtml(@RequestParam(value="name", required=false, defaultValue="sh14") String name) throws Exception {
        String json = "prueba json";

        String contentType = ?????

        if(contentType.equals("application/json")){
            return json;
        }else{
            ModelAndView mav = new ModelAndView();
            mav.setViewName("gestores");
            mav.addObject("name", name);
            return mav;
        }
    }
}

谢谢大家