Springboot Thymeleaf form validation not working - forms

Question

I've trying to validate the fields in Thymeleaf but the errors are not showing in the view page.
My Controller
#Controller
public class UserController {
private static final String ADD_NEW_USER="user/addUser";
#Autowired
UserService userService;
#RequestMapping(value="/user/new", method=RequestMethod.GET)
public String addUser(Registration register, Model model){
model.addAttribute("register",register);
return ADD_NEW_USER;
}
#RequestMapping(value="/user/new", method=RequestMethod.POST)
public String addUser(#Valid Registration register, BindingResult result, Model model){
model.addAttribute("register",register);
if(result.hasErrors()){
List<FieldError> err=result.getFieldErrors();
for(FieldError e:err){
System.out.println("Error on object ---> "+e.getObjectName()+" on field ---> "+e.getField()+". Message ---> "+e.getDefaultMessage());
}
return ADD_NEW_USER;
}
return INDEX_PAGE;
}
}
View template
<form th:action="#{/user/new}" th:method="post" th:object="${register}" id="addUser" role="form">
<fieldset>
<legend>
<p>Field with <span class="required">*</span> are required</p>
</legend>
<div class="form-group">
<label for="name"><span class="required">* </span>Name: </label>
<input type="text" th:field="*{name}" class="form-control" />
<div th:if="${#fields.hasErrors('name')}" th:errors="*{name}" class="alert alert-danger">
<p>Name is invalid</p>
</div>
<p class="help-block">Please provide full name for the user</p>
</div>
<div class="form-group">
<label for="email"><span class="required">* </span> Email Address: </label>
<input class="form-control" type="email" th:field="*{email}"/>
<div th:if="${#fields.hasErrors('email')}" th:errors="*{email}" class="alert alert-danger">
<p>Email is invalid</p>
</div>
<p class="help-block">Please provide a valid email address. Activation link will be sent to this email</p>
</div>
<div class="form-group">
<label for="password"><span class="required">* </span> Password: </label>
<input type="password" th:field="*{password}" class="form-control"/>
</div>
<div class="form-group">
<input class="btn btn-success" type="submit" name="Register" value="Register"/>
</div>
</fieldset>
</form><!-- ends register form -->
Modal
#Entity
public class Registration {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private Long id;
#NotEmpty
#Size(min=3, max=50)
#Column(nullable=false)
private String name;
#Email
#NotEmpty
#Column(nullable=false)
private String email;
private String password;
//getters and setters
}
I can output the console error like this.
Error on object ---> registration on field ---> name. Message ---> size must be between 3 and 50
Error on object ---> registration on field ---> email. Message ---> may not be empty
Error on object ---> registration on field ---> name. Message ---> may not be empty
I might be missing something but unable to find.

Answer 1

the problem is that the name of the entity is Registration and that the name of the object that you use is register.
In order this to work add #ModelAttribute("register") next yo your #valid annotation
namely
#RequestMapping(value="/user/new", method=RequestMethod.POST)
public String addUser(#Valid #ModelAttribute("register") Registration register, BindingResult result, Model model){
Hope this helps

Answer 2

I was also facing the same issue. With may hit/trial approach I found that #Valid annotation doesn't work with spring 2.3.0.RELEASE
If you are using spring 2.3.0.RELEASE then add below dependency
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>
Hope this helps.

Answer 3

I also faced the same issue. My bindingResult.hasErrors() was always returning true in spite of pulling no values in the form. I had to change my validation from #NotNull to #NotEmpty.
#NotNull will only validate if the object is null, #NotEmpty will check if the object has empty strings.