public class ConstraintValidatorContext {

    addInterpolatedParameter(String name, String value);

}

public class SyntaxValidator implements ConstraintValidator<Syntax, String> {

    public boolean isValid(String value, ConstraintValidatorContext context) {

        detectedSyntax = ...;

        context.addInterpolatedParameter("detectedSyntax", detextedSyntax);

        return allowedSyntaxes.contains(detectedSyntax);

    }

}

@Syntax(value={JAVA, HTML}, message="{constraint.syntax}")

String text;

ValidatorMessage_en.properties

constraint.syntax=Unable to support {detectedSyntax}

=>

"Unable to support PHP"