how to set locale for java bean validations in spring

Old note from 2017-05-17. May be outdated.

Using JSR303 Java bean validations is great! Using with hibernate validation annotations is also great as it provides default validations like @NotBlank.

However, the hibernate validation library also provides default validation messages, for several languages (which is great). You just need to instanciate a new bean org.springframework.web.servlet.i18n.FixedLocaleResolver in your app configuration:

@Configuration
public class OneLocaleValidatorConfig {
    @Bean
    LocaleResolver localeResolver() {
        // Force english for Spring Security error messages
        return new FixedLocaleResolver(Locale.ENGLISH);
    }
}

Update: The following solution works but it’s not the ideal way to force the locale.

One way is to provide our own MessageSource and define our own properties files, thus having only one message properties file for only one locale.

• Create a configuration file:

@Configuration
public class OneLocaleValidatorConfig extends WebMvcConfigurerAdapter {
    @Override
    public Validator getValidator() {
        LocalValidatorFactoryBean factory = new LocalValidatorFactoryBean();
        factory.setValidationMessageSource(messageSource());
        return factory;
    }
 
    private MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        // Set our own validation message property so we only have english version
        messageSource.setBasename("classpath:validation/OneLocaleValidationMessages");
        messageSource.setDefaultEncoding(StandardCharsets.UTF_8.displayName());
        return messageSource;
    }
}

• Add only one validation messages in the /path/to/project/src/main/resources/validation/OneLocaleValidationMessages.properties with the content provided by the hibernate validation library:

javax.validation.constraints.AssertFalse.message = must be false
javax.validation.constraints.AssertTrue.message  = must be true
javax.validation.constraints.DecimalMax.message  = must be less than ${inclusive == true ? 'or equal to ' : ''}{value}
javax.validation.constraints.DecimalMin.message  = must be greater than ${inclusive == true ? 'or equal to ' : ''}{value}
javax.validation.constraints.Digits.message      = numeric value out of bounds (<{integer} digits>.<{fraction} digits> expected)
javax.validation.constraints.Future.message      = must be in the future
javax.validation.constraints.Max.message         = must be less than or equal to {value}
javax.validation.constraints.Min.message         = must be greater than or equal to {value}
javax.validation.constraints.NotNull.message     = may not be null
javax.validation.constraints.Null.message        = must be null
javax.validation.constraints.Past.message        = must be in the past
javax.validation.constraints.Pattern.message     = must match "{regexp}"
javax.validation.constraints.Size.message        = size must be between {min} and {max}
 
org.hibernate.validator.constraints.CreditCardNumber.message        = invalid credit card number
org.hibernate.validator.constraints.EAN.message                   = invalid {type} barcode
org.hibernate.validator.constraints.Email.message                   = not a well-formed email address
org.hibernate.validator.constraints.Length.message                  = length must be between {min} and {max}
org.hibernate.validator.constraints.LuhnCheck.message               = The check digit for ${validatedValue} is invalid, Luhn Modulo 10 checksum failed
org.hibernate.validator.constraints.Mod10Check.message              = The check digit for ${validatedValue} is invalid, Modulo 10 checksum failed
org.hibernate.validator.constraints.Mod11Check.message              = The check digit for ${validatedValue} is invalid, Modulo 11 checksum failed
org.hibernate.validator.constraints.ModCheck.message                = The check digit for ${validatedValue} is invalid, ${modType} checksum failed
org.hibernate.validator.constraints.NotBlank.message                = may not be empty
org.hibernate.validator.constraints.NotEmpty.message                = may not be empty
org.hibernate.validator.constraints.ParametersScriptAssert.message  = script expression "{script}" didn't evaluate to true
org.hibernate.validator.constraints.Range.message                   = must be between {min} and {max}
org.hibernate.validator.constraints.SafeHtml.message                = may have unsafe html content
org.hibernate.validator.constraints.ScriptAssert.message            = script expression "{script}" didn't evaluate to true
org.hibernate.validator.constraints.URL.message                     = must be a valid URL
 
org.hibernate.validator.constraints.br.CNPJ.message                 = invalid Brazilian corporate taxpayer registry number (CNPJ)
org.hibernate.validator.constraints.br.CPF.message                  = invalid Brazilian individual taxpayer registry number (CPF)
org.hibernate.validator.constraints.br.TituloEleitoral.message      = invalid Brazilian Voter ID card number