Customizing Validator Messages
Bean Validation includes a resource bundle of default messages for the built-in constraints. These messages can be customized and can be localized for non-English-speaking locales.
The following topics are addressed here:
The ValidationMessages Resource Bundle
The ValidationMessages resource bundle and the locale variants of this
resource bundle contain strings that override the default validation
messages. The ValidationMessages resource bundle is typically a
properties file, ValidationMessages.properties, in the default package
of an application.
Localizing Validation Messages
Locale variants of ValidationMessages.properties are added by
appending an underscore and the locale prefix to the base name of the
file. For example, the Spanish locale variant resource bundle would be
ValidationMessages_es.properties.