在以下示例中,ScriptFile
参数用@Valid
注释标记。@Valid
注释有什么作用?
@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();
}
最佳答案
这是出于验证目的。
在这里查看更多信息:
http://blog.springsource.com/2009/11/17/spring-3-type-conversion-and-validation/