Create a validation method which throw MethodArgumentNotValidException

Question

I'm trying to validate this class :

public class RegisterRequest {
    @Email(message = "format e-mail non valide") @NotNull(message = "ne doit pas être vide")
    private String email;
    @NotEmpty(message = "ne doit pas être vide")
    @NotBlank(message = "ne doit pas être vide")
    @NotNull(message = "ne doit pas être vide")
    private String prenom;
    @NotEmpty(message = "ne doit pas être vide")
    @NotBlank(message = "ne doit pas être vide")
    @NotNull(message = "ne doit pas être vide")
    private String nom;
    @Length(min = 13,max = 13 ,message = "doit contenir exactement 13 chiffres")
    @NotNull(message = "ne doit pas être vide")
    @Pattern(regexp = "^\\d*$", message = "ne doit contenir que des chiffres")
    @Pattern(regexp = "^[12]\\w*$", message = "doit commencer par 1 ou 2")
    private String cin;
    @NotNull(message = "ne doit pas être vide")
    @Pattern(regexp = "^(?!.*  .*)[\\d+() ]{9,20}$", message = "ne doit contenir que des chiffres , des parentheses et plus")
    @Length(min = 9,max = 20)
    private String telephone;
    @NotNull(message = "ne doit pas être vide")
    @Length(min = 5,max = 20,message = "la taille de caractère doit être entre 5 et 20")
    @Pattern(regexp = "^(?=[a-zA-Z\\d._-]*$)(?!.*[_.]{2})[^_.].*[^_.]$",message = "ne doit contenir de caractère special  a part _ , .,-")
    private String login;
}

after construction with ObjectMapper like this :

@PostMapping("/register")
public ResponseEntity<?> register(
            @RequestParam("file") MultipartFile file,
            @RequestParam Map<String,Object> req
     ) throws UserNotFoundException, EntreeException, RoleNotFoundException, IOException {
        ObjectMapper mapper = new ObjectMapper();
        RegisterRequest registerRequest = mapper.convertValue(req,RegisterRequest.class);
        return controllerResponse(registerRequest,"");
    }

as you see i can't use the @Valid annotation here (note : if there is a method to use the annotation directly i'll prefere it. but i didnt find any way to do it.
so i've found that it is better to create a validator class so after some research i've found this method

@Slf4j
public class CustomValidator {
    ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
    Validator validator = factory.getValidator();
    public Boolean validate(Object object){
        Set<ConstraintViolation<Object>> violations = validator.validate(object);
        log.info(violations.toString());
        String errorMessage =
                violations.stream().map(ConstraintViolation::getMessage).collect(Collectors.joining(", "));
        throw new MethodArgumentNotValidException(errorMessage);
    }
}

but it is not working take two argument in his constructor :

 MethodParameter parameter, BindingResult bindingResult

so my question is how create this argument and how to throw it like @Valid throw it or is there any other way to handle the validation error

Answer 1

So, i've found this solution but i'm not throwing MethodArgumentNotValidException anymore i've created my own exception class like this :

@Getter @Setter
public class ArgumentValidationExption extends Exception{
    private final Map<String, String> errors;
    public ArgumentValidationExption(Map<String,String> errors) {
        super();
        this.errors = errors;
    }

@ExceptionHandler(ArgumentValidationExption.class)
    public ResponseEntity<?> ArgumentInvalid(ArgumentValidationExption arg){
        return jsonResponse(false,arg.getErrors(),400,arg.getClass().getSimpleName());
    }

and in my validator class ill just throw my exception like this :

public void validate(Object object) throws ArgumentValidationExption {
        Set<ConstraintViolation<Object>> violations = validator.validate(object);
        if (violations.size() == 0 ) return ; 
        Map<String, String> errors = new HashMap<>();

        for (ConstraintViolation<Object> constraint: violations
             ) {
            errors.put(constraint.getPropertyPath().toString(), constraint.getMessageTemplate());
        }
        throw new ArgumentValidationExption(errors);
        
    }
}

if you found a better solution please let me know