Spring MVC validator annotation + custom validation

Question

I'm working on spring mvc application, where I should aplly validation based on Spring MVC validator. I first step for that I added annotation for class and setup controller and it works fine. And now I need to implement custom validator for perform complex logic, but i want to use existing annotation and just add additional checking.

My User class:

public class User {     @NotEmpty     private String name;      @NotEmpty     private String login; // should be unique } 

My validator:

@Component public class UserValidator implements Validator {      @Autowired     private UserDAO userDAO;      @Override     public boolean supports(Class<?> clazz)     {         return User.class.equals(clazz) || UsersForm.class.equals(clazz);     }      @Override     public void validate(Object target, Errors errors)     {         /*         ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "NotEmpty.user");         ValidationUtils.rejectIfEmptyOrWhitespace(errors, "login", "NotEmpty.user");         */         User user = (User) target;         if (userDAO.getUserByLogin(user.getLogin()) != null) {             errors.rejectValue("login", "NonUniq.user");         }     } } 

My controller:

@Controller public class UserController {     @Autowired     private UserValidator validator;      @InitBinder     protected void initBinder(final WebDataBinder binder)     {         binder.setValidator(validator);     }      @RequestMapping(value = "/save")     public ModelAndView save(@Valid @ModelAttribute("user") final User user,             BindingResult result) throws Exception     {         if (result.hasErrors())         {             // handle error         } else         {             //save user         }     } } 

So, Is it possible to use custom validator and annotation together? And if yes how?

Answer 1

I know this is a kind of old question but, for googlers...

you should use addValidators instead of setValidator. Like following:

@InitBinder protected void initBinder(final WebDataBinder binder) {     binder.addValidators(yourCustomValidator, anotherValidatorOfYours); } 

PS: addValidators accepts multiple parameters (ellipsis)

if you checkout the source of org.springframework.validation.DataBinder you will see:

public class DataBinder implements PropertyEditorRegistry, TypeConverter {      ....      public void setValidator(Validator validator) {         assertValidators(validator);         this.validators.clear();         this.validators.add(validator);     }      public void addValidators(Validator... validators) {         assertValidators(validators);         this.validators.addAll(Arrays.asList(validators));     }      ....  } 

as you see setValidator clears existing (default) validator so @Valid annotation won't work as expected.