Get entity name from class object

This should always work (no return of Proxy class):

$em = $this->container->get('doctrine')->getEntityManager(); 
$className = $em->getClassMetadata(get_class($object))->getName();

As getClassMetadata is deprecated, you can now use getMetadataFor

$entityName = $this->em->getMetadataFactory()->getMetadataFor(get_class($object))->getName();

PHP get_class() function will return User and namespace (see comments in php docs).

getClassMetadata() is deprecated and will be removed in the future. Use getMetadataFor() instead:

$entityName = $this->em->getMetadataFactory()->getMetadataFor(get_class($entity))->getName();

Or a complete function:

/**
 * Returns Doctrine entity name
 *
 * @param mixed $entity
 *
 * @return string
 * @throws \Exception
 */
private function getEntityName($entity)
{
    try {
        $entityName = $this->em->getMetadataFactory()->getMetadataFor(get_class($entity))->getName();
    } catch (MappingException $e) {
        throw new \Exception('Given object ' . get_class($entity) . ' is not a Doctrine Entity. ');
    }

    return $entityName;
}