spring - org.springframework.validation.BeanPropertyBindingResult 异常

Question

嗨，我是 Spring 框架的新手。我做了一个小例子，我尝试使用 spring 验证 api 验证我的输入字段。这是代码

@RequestMapping(value = "/applicationFormSubmit", method = RequestMethod.POST)
    public String insertdata( @ModelAttribute("applicationForm") @Valid ApplicationFormBean applicationFormBean, @RequestParam("file") MultipartFile file, BindingResult result,Model model)
{
    if(result.hasErrors())
    {

        return "applicationForm";           
    }
      try {
            Blob blob = Hibernate.createBlob(file.getInputStream());

          //  applicationFormBean..setFilename(file.getOriginalFilename());
            applicationFormBean.setSignature(blob);
          //  applicationFormBean.setContentType(file.getContentType());
        } catch (IOException e) {
            e.printStackTrace();
        }
    applicationFormUserService.insertApplicationData(applicationFormBean);

    return "applicationForm";       

}

但是当我用空白值提交 from 时，它给了我以下错误

Field error in object 'applicationForm' on field 'applicantName': rejected value []; codes [NotEmpty.applicationForm.applicantName,NotEmpty.applicantName,NotEmpty.java.lang.String,NotEmpty]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [applicationForm.applicantName,applicantName]; arguments []; default message [applicantName]]; default message [Please enter your nnnn.]

Field error in object 'applicationForm' on field 'applicantName': rejected value []; codes [Size.applicationForm.applicantName,Size.applicantName,Size.java.lang.String,Size]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [applicationForm.applicantName,applicantName]; arguments []; default message [applicantName],20,2]; default message [this is worng ]

Answer 1

请更改代码中的行，如下所示。

public String insertdata(
    @ModelAttribute("applicationForm") @Valid ApplicationFormBean applicationFormBean,
    BindingResult result,
    Model model,
    @RequestParam("file") MultipartFile file)

如 this Spring MVC tutorial 中所述:

The BindingResult must come right after the model object that is validated or else Spring will fail to validate the object and throw an exception.

This tutorial也提到了这个问题。