User.php

<?php

namespace AppBundle\Entity;

class User extends BaseUser
{
    // properties, getters and setters
}

UserController.php

<?php

namespace AppBundle\Controller;

class UserController
{
    /**
     * @return User[]
     */
    public function getUsersAction()
    {
        return $this->userManager->retrieveUsers();
    }
}

UserManager.php

<?php

namespace AppBundle\Service;

class UserManager
{
    /**
     * @return User[]
     */
    public function retrieveUsers()
    {
        $this->userRepository->getAllUsers();
    }
}

UserRepository.php

<?php

namespace AppBundle\Repository;

class UserRepository extends EntityRepository
{
    /**
     * @return User[]
     */
    public function getAllUsers()
    {
        return $this->findAll();
    }
}