form validation in spring in action 5

Question

I am following the source code of spring in action 5 on github, and I code my own version. When I leave the name blank and commit, I get a wrong page like that

and the console output is: Field error in object 'taco' on field 'name': rejected value [];

But the correct page is like that:

here is my code:

design.html

 <label>give it a name:</label>

 <input type="text" th:field="*{name}">

  <span class="validationError"
      th:if="${#fields.hasErrors('name')}"
      th:errors="*{name}">Name Error</span>

designController.java

    @PostMapping
    public String postTaco(@Valid Taco taco, Order order, Errors errors) {
        if (errors.hasErrors()){
            return "design";
        }

        Taco taco1 = tacoRepo.save(taco);
        order.addDesign(taco1);
        return "order";
    }

Taco.java

@Size(min=5, message = "at least 5 characters")
private String name;

Answer 1

Where is the problem

designContrller.java

    @PostMapping
    public String postTaco(@Valid Taco taco, Order order, Errors errors) {
        if (errors.hasErrors()){
            return "design";
        }

        Taco taco1 = tacoRepo.save(taco);
        order.addDesign(taco1);
        return "order";
    }

solution：

    @PostMapping
    public String postTaco(@Valid Taco taco, Errors errors, Order order) {
        if (errors.hasErrors()){
            return "design";
        }

        Taco taco1 = tacoRepo.save(taco);
        order.addDesign(taco1);
        return "order";
    }

conclusiong:

The parameter Erroes errors must behide the valid object parameter, here is Taco taco