Ejemplo de uso de Validator

CountryService.php

<?php
namespace Services;

use Models\CountryMapper;
use Billing\Services\ServiceValidator;

use Symfony\Component\Validator\Constraints\NotNull;

class Country
{
    private $_countryMapper;

    private $_validator;

    public function __construct(ServiceValidator $validator,
                                CountryMapper $countryMapper)
    {
        $this->_countryMapper = $countryMapper;
        $this->_validator = $validator;
    }

    public function getAction($params)
    {
        $this->_validator->validate(
            $params, array(
                "siteId" => new NotNull(),
                "countryId" => new NotNull()
            )
        );

        return $this->_countryMapper->getConfig(
            $params["siteId"],
            $params["countryId"]
        );
    }
}