Spring ROO Serverside validation doesn't work

Answer 1

1st of all spring-roo is not to blame for this, spring by default uses java property editor for String which converts it to empty string if no value is provide.

Springs own StringTrimmerEditor can be used inside controllers as shown below.

@InitBinder
    public void initBinder(WebDataBinder binder) {
        binder.registerCustomEditor(String.class, new StringTrimmerEditor(Boolean.TRUE));
    }