Hibernate form validation doesn't pick up errors

[Saggi Oscuro]

I'm new to spring and have been trying to get a simple validation form working.

When I submit the form with an empty string for the playerName, the validation error does not get picked up in the controller and continues forward.

Here's what I have so far :

Participant.java

import javax.validation.constraints.NotBlank;
import javax.validation.constraints.Size;

ParticipantController.java

public class Participant {
    
    @NotBlank
    @Size(min=1,message="is required")
    private String playerName;

     ...

    public String getPlayerName() {
        return playerName;
    }

    public void setPlayerName(String playerName) {
        this.playerName = playerName;
    }

participant-form.jsp

<form:form action="processForm" modelAttribute="participant" method="POST">
        nickname : <form:input path="playerName" />
        <form:errors path="playerName" cssCalss="error"/>

ParticipantController.java

@PostMapping("/processForm")
    public String processForm(
            @Valid @ModelAttribute("participant")Participant theParticipant,
            Model model, BindingResult result)
    {
        if(result.hasErrors())
        {
            return "participant-form";
        }
        
        
        model.addAttribute("participant",theParticipant);
        
        return]"participant-confirmation";
    }

pom.xml

<dependencies>
        <!-- Servlet API Dependency -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>3.0-alpha-1</version>
        </dependency>
        <!-- Spring Framework Dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.0.6.RELEASE</version>
        </dependency>
        <!-- jar is used for showing the server side validations in the spring 
            framework -->
        <dependency>
            <groupId>org.hibernate.validator</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>6.0.10.Final</version>
        </dependency>
    </dependencies>

[Himai Minh]

I think you may need this dependency as well :

<dependency>
    <groupId>javax.validation</groupId>
    <artifactId>validation-api</artifactId>
    <version>2.0.1.Final</version>
</dependency>

Reference:
https://www.baeldung.com/javax-validation

[Himai Minh]

Hi, Saggi
Another question for you is, what spring boot version do you use ?

[Himai Minh]

Hi, Saggi,
Depending on what spring boot version you are using, you may need to include different dependency for validation.
Here is a helpful article:

https://stackoverflow.com/questions/48614773/spring-boot-validation-annotations-valid-and-notblank-not-working