Thymeleaf not displaying Spring form error messages

Question

I\'m migrating a Spring jsp application to Thymeleaf but having problems displaying form errors.

I\'m using the SpringTemplateEngine and ThymeleafViewResolver and re

Answer 1

This is how I do it in my forms:

For displaying all errors I put this at the beginning of my form:

<div class="alert alert-danger" th:if="${#fields.hasErrors('*')}">
    <p th:each="err : ${#fields.errors('*')}" th:text="${err}"></p>    
</div>

and for individual error I add this after the field (of course, changing field in hasErrors to correspond to the field tested):

<p th:if="${#fields.hasErrors('vehicle.licensePlate')}" class="label label-danger" th:errors="*{vehicle.licensePlate}">Incorrect LP</p>

Let me know if this works for you?

Answer 2

I think you may be having the same issue as I did - please see :

• Fields object functions (Spring)

There it is answered by Daniel Fernandez. Basically your form object th:object="${form}" is named "form" but your controller is looking for "customerForm" (class name) not "form" (the variable name)

can be renamed with @ModelAttribute("data")

copied from that link use:

public String post(@Valid FormData formData, BindingResult result, Model model){
    // th:object="${formData}"
}

or

public String post(@Valid @ModelAttribute("data") FormData data, BindingResult result, Model model){
    // th:object="${data}"
} 

Answer 3

Adding to @Blejzer answer: naming of error message inside messages.properties file must follow below naming convention, so message string will be returned instead of message key:

(Constraint Name).(Object Name).(Property Name)

note: Object Name not Class Name

For example, if you have below User class:

class User{
    @NotBlank
    String username;

    @Length(min=6)
    String password;
}

suppose in controller, we named object under validation "user", see @ModelAttribute("user"):

@RequestMapping(value = "/signup", method = RequestMethod.POST)
public String signup(@Valid @ModelAttribute("user") User user, BindingResult bindingResult, Model model) {

    if (bindingResult.hasErrors()) {
        return "signup";
    }

    //do some processing

    return "redirect:/index";
}

in above controller snippet, the object name is "user" not "User"

Now, to show custom messages, you have to name the message as below:

NotBlank.user.username=User Name is blank
Length.user.password=Password length must be at least 6 letters