在以下示例中，该ScriptFile参数标记有@Valid注释。

是什么@Valid注解吗？

@RequestMapping(value = "/scriptfile", method = RequestMethod.POST)    
public String create(@Valid ScriptFile scriptFile, BindingResult result, ModelMap modelMap) {    
    if (scriptFile == null) throw new IllegalArgumentException("A scriptFile is required");        
    if (result.hasErrors()) {        
        modelMap.addAttribute("scriptFile", scriptFile);            
        modelMap.addAttribute("showcases", ShowCase.findAllShowCases());            
        return "scriptfile/create";            
    }        
    scriptFile.persist();        
    return "redirect:/scriptfile/" + scriptFile.getId();        
}