@NotEmpty(message = "validation.firstname.NotEmpty.message")
    @Size(min = 3, max = 60, message = "validation.firstname.Size.message")
    @Column(name = "FIRST_NAME")
    private String firstName;

    @NotEmpty(message = "validation.lastname.NotEmpty.message")
    @Size(min = 2, max = 40, message = "validation.lastname.Size.message")
    @Column(name = "LAST_NAME")
    private String lastName;

alidation.firstname.NotEmpty.message=Имя не может быть пустым
validation.firstname.Size.message=Длинна имени от 3 до 60 символов
validation.lastname.NotEmpty.message=Фамилия не может быть пустая
validation.lastname.Size.message=Длинна фамилии от 2 до 40 символов

@Bean
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setBasename("/WEB-INF/il8n/messages");
        messageSource.setDefaultEncoding("UTF-8");
        messageSource.setFallbackToSystemLocale(false);
        return messageSource;
    }
 @Bean
    public LocalValidatorFactoryBean validator() {
        LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
        validator.setProviderClass(HibernateValidator.class);
        validator.setValidationMessageSource(messageSource());
        return validator;
    }
    @Bean
    public MethodValidationPostProcessor methodValidationPostProcessor() {
        MethodValidationPostProcessor mvProcessor = new MethodValidationPostProcessor();
        mvProcessor.setValidator(validator());
        return mvProcessor;
    }

<dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.2.4.Final</version>
        </dependency>