在Spring Boot App中使用@Valid和BindingResult进行表单输入验证时出现问题

Question

I am trying to add code-side validation to my form. I am basing on this tutorial: https://www.javacodegeeks.com/2017/10/validation-thymeleaf-spring.html - but without effort.

I have an entity InvoiceData:

@Data
@Document
@NoArgsConstructor
public class InvoiceData {

    @Id private String id;
    private ContractorData data;
    @NotNull
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date receptionDate;
    @NotNull
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date orderDate;
    @NotNull
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date invoiceIssueDate;
    @NotNull
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    @NotNull
    private Date contractDate;
    @NotBlank
    private String invoiceNumber;
    private String additionalCosts;
    private String contractorComment;
    @NotEmpty
    private List<InvoiceTask> invoiceTasks = new ArrayList<>();

And a Controller method:

@RequestMapping(value = "/addinvoice/{contractorId}", method = RequestMethod.POST, produces = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
    public String addInvoice(@PathVariable("contractorId") String contractorId, @ModelAttribute @Valid InvoiceData data, Model model, BindingResult result, RedirectAttributes attr, HttpSession session) {
        if (result.hasErrors()) {
            System.out.println("BINDING RESULT ERROR");
            attr.addFlashAttribute("org.springframework.validation.BindingResult.data", result);
            attr.addFlashAttribute("register", result);
            return "redirect:/add";
        } else {
            Contractor contractor = contractorRepository.findById(contractorId).get();
            data.setData(contractor.getContractorData());
            if (contractor.getInvoices() == null) {
                contractor.setInvoices(new ArrayList<InvoiceData>());
            }
            contractor.getInvoices().add(data);
            invoiceDataRepository.save(data);
            contractorRepository.save(contractor);
            model.addAttribute("contractor", contractor);
            return "index";
        }
    }

And a small piece of the Thymeleaf for clearness (all other fields look alike this one)

<form action="#" th:action="@{addinvoice/{id}(id=${contractorid})}" th:object="${invoicedata}" method="post">
    <ul class="form-style-1">
        <li>
            <label>Reception date<span class="required">*</span></label>
            <input type="date" th:field="*{receptionDate}" id="receptionDate">
        </li>

The problem is that when I am trying to send an invalid form, I am not redirected to /add , but I get an error page saying:

There was an unexpected error (type=Bad Request, status=400). Validation failed for object='invoiceData'. Error count: 6

And the stacktrace (from just one field, for clearness):

Field error in object 'invoiceData' on field 'invoiceIssueDate': rejected value [null]; codes [NotNull.invoiceData.invoiceIssueDate,NotNull.invoiceIssueDate,NotNull.java.util.Date,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [invoiceData.invoiceIssueDate,invoiceIssueDate]; arguments []; default message [invoiceIssueDate]]; default message [must not be null]

So I presume that this is one of the behaviours that I can exptect from the validator.

But there is one thing, when I set a breakpoint in the controller, at the beginning of the method where the if statement begins, AND I send an invalid form, the debugger never stops there, so it seems that this code is never reached...

But when I send a correctly filled form - everything goes fine, the code works, data is sent to the database etc...

My question is: is this a normal behaviour of the validator? What can I do make the code run when form is invalid, so I can get the BindingResult and show some error output to the user?

Answer 1

You need to move the BindingResult parameter right next to parameter having @Valid annotation.

@RequestMapping(value = "/addinvoice/{contractorId}", method = RequestMethod.POST, produces = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
public String addInvoice(@PathVariable("contractorId") String contractorId, @ModelAttribute @Valid InvoiceData data, BindingResult result, Model model , RedirectAttributes attr, HttpSession session) {
    if (result.hasErrors()) {
        System.out.println("BINDING RESULT ERROR");
        attr.addFlashAttribute("org.springframework.validation.BindingResult.data", result);
        attr.addFlashAttribute("register", result);
        return "redirect:/add";
    } else {
        Contractor contractor = contractorRepository.findById(contractorId).get();
        data.setData(contractor.getContractorData());
        if (contractor.getInvoices() == null) {
            contractor.setInvoices(new ArrayList<InvoiceData>());
        }
        contractor.getInvoices().add(data);
        invoiceDataRepository.save(data);
        contractorRepository.save(contractor);
        model.addAttribute("contractor", contractor);
        return "index";
    }
}

Now the BindingResult variable will be attached to InvoiceData variable. Also if you are Validating multiple parameters in a API, you would require to declare its corresponding BindingResult variable right next to all of these.