Erro hibernate com constraint customizada (bean validation)

package br.edu.dmsoftware.tcc.validator;

    import javax.inject.Inject;
    import javax.validation.ConstraintValidator;
    import javax.validation.ConstraintValidatorContext;

    import br.edu.dmsoftware.tcc.annotation.UniqueEmail;
    import br.edu.dmsoftware.tcc.dao.UsuarioDao;

    public class UniqueEmailValidator implements ConstraintValidator<UniqueEmail, String> {
        
        @Inject
        private UsuarioDao usuarioDao;
        
        @Override
        public void initialize(UniqueEmail constraintAnnotation) {}

        @Override
        public boolean isValid(String email, ConstraintValidatorContext context) {
            if(usuarioDao.emailExiste(email)){
                return false;
            }
            return true;
        }
        
    }




package br.edu.dmsoftware.tcc.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

import br.edu.dmsoftware.tcc.validator.UniqueEmailValidator;
//Linkando classe validadora
@Constraint(validatedBy = {UniqueEmailValidator.class})
//Essa constraint pode ser utilizado somente por catributos e métodos
@Target({ElementType.FIELD, ElementType.METHOD})
@Retention(value = RetentionPolicy.RUNTIME)
@Documented
public @interface UniqueEmail {
    // Mensagem quando o e-mail existir
    String message() default "Este e-mail já está em uso";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};
}