$repository = $this->getDoctrine()->getRepository(User::class);
$users = $repository->findAll();

Array (
            [0] => AppBundleEntityUser Object ( [id:AppBundleEntityUser:private] => 1 [roll:AppBundleEntityUser:private] => 1 [name:AppBundleEntityUser:private] => kumar [password:AppBundleEntityUser:private] => 123456 )
            [1] => AppBundleEntityUser Object ( [id:AppBundleEntityUser:private] => 2 [roll:AppBundleEntityUser:private] => 2 [name:AppBundleEntityUser:private] => arpan [password:AppBundleEntityUser:private] => 1234 )
            [2] => AppBundleEntityUser Object ( [id:AppBundleEntityUser:private] => 3 [roll:AppBundleEntityUser:private] => 3 [name:AppBundleEntityUser:private] => Bumba [password:AppBundleEntityUser:private] => abcd )
        )