| FormErrors | A container of field and one or more associated errors, to be displayed in a form. | 
| BaseUrlValidator<T extends Annotation> | Base class to validate the base URL of the HTTP and SSH protocols. | 
| ConditionalNotEmptyValidator | |
| ConstraintNature | |
| ConstraintNature.Conflict | |
| FieldEqualsValidator | Validate that multiple fields are identical. | 
| HttpURLValidator | Validate that the string is a valid http or https URL. | 
| IntegerValidator | Validate a value can be converted to an Integer,
 optionally validating whether the number is positive. | 
| IntValidator | Validator for the Intannotation. | 
| NonNegativeIntValidator | Validator for the NonNegativeIntannotation. | 
| OptionalStringValidator | Validator for the OptionalStringannotation. | 
| RequiredUriValidator | Validates an object annotated with RequiredUri | 
| SimpleFormErrors | Simple implementation of FormErrorsas a plain Java object with a builder, | 
| SimpleFormErrors.Builder | 
| ArgumentValidationException | |
| FormValidationException | Exception to represent possible validation errors. |