springMVC如何跨域请求-jsonp

前端 

$.getJSON(" http://ip/example/getStudentById?jsoncallback=jsonp1236827957501",function(json){
       
 });

spring MVC端

@RequestMapping(value="getStudentById" ,produces = "text/html;charset=UTF-8")
public String sso(HttpServletRequest request, HttpServletResponse response) {

StringBuilder result = new StringBuilder();
result.append(request.getParameter("jsoncallback")).append('(').append("{}").append(')');
return result.toString();
}