Hi All, I'm trying to build a controller like this: @RequestMapping(method = {RequestMethod.GET}, value = "/users/detail/activities.do") public View foo(@RequestParam(value = "userCash", defaultValue="0.0") Double userCash) { System.out.println("foo userCash=" + userCash); } This works fine: http://localhost/app/users/detail/activities.do?userCash=123& but in this one userCash==null despite the default value http://localhost/app/users/detail/activities.do?userCash=& From some digging it seems like the first one works b/c of a Editor binding like this: binder.registerCustomEditor(Double.class, new CustomNumberEditor(Double.class, false)); The trouble is that the second param (ie false) defines whether blank values are allowed. If i set that to true, than the system considers the blank input as valid so i get a null Double class. If i set it to false then the system chokes on the blank input string with: org.springframework.beans.TypeMismatchException: Failed to convert value of type 'java.lang.String' to required type 'double'; nested exception is java.lang.NumberFormatException: empty String Does anyone know how to get the defaultValue to work for Doubles? Thanks --Matthias