Spring boot + Thymeleaf custom error messages

Question

I am using spring boot and thymeleaf for a web application.

I want to customize the validation error messages instead of using the default ones. I found the way to do it is creating a file called messages.properties with the constraints and the message. I also found I can create custom messages based on the class I am targeting and I can also use internationalization methods based on this.

In order to override the default messages I created my own messages.properties file:

Size.message=El tamño no es correcto
NotNull.message=No puede ser nulo
Min.message=No cumple con el minimo

I set the constraints in my class:

public class Person {

    @Size(min=2, max=30)
    private String name;

    @NotNull
    @Min(value = 18L)
    private Integer age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

This is my form:

<form action="#" th:action="@{/form}" th:object="${person}" method="post">

    <table>
        <tr>
            <td>Name:</td>
            <td><input type="text" th:field="*{name}"/></td>
            <td th:if="${#fields.hasErrors('name')}" th:errors="*{name}">Name error</td>
        </tr>
        <tr>
            <td>Age:</td>
            <td><input type="text" th:field="*{age}"/></td>
            <td th:if="${#fields.hasErrors('age')}" th:errors="*{age}">Name error</td>
        </tr>
        <tr>
            <td>
                <button type="submit">Enviar</button>
            </td>
        </tr>
    </table>

</form>

And I placed the messages.properties in the resources folder:

According to these links I am doing correctly:

Thymeleaf : How to use Custom Message Key in JSR-303 Annotation

How to include message.properties with thymeleaf

But it still not display the custom error messages I wrote.

Any suggestion? Thanks in advance for your help.

GitHub with the sample code: https://[email protected]/MichaelKnight/ValidandoFormularios.git

Answer 1

Because you are using JSR-303 validators then you should place your messages to the file named ValidationMessages.properties. JSR-303 provider (hibernate-validator, in this case) looks by default for this file (as per specification).

See for details: https://docs.jboss.org/hibernate/validator/5.1/reference/en-US/html/chapter-message-interpolation.html