Symfony3 - Define service outside src/bundle - symfony

Question

I am trying to define service outside src, in App\Service to be exact. I know that service in Symfony is just a class therefore I should be able to put it anywhere.
That's what I've got at the moment:
app\config\services.yml
parameters:
serializer_service_class: App\Service\SerializeService
services:
app.serializer:
class: '%serializer_service_class%'
autowire: true
Service is just a simple serializing class:
SerializeService.php
<?php
namespace App\Service;
use Symfony\Component\Serializer\Encoder\JsonEncoder;
use Symfony\Component\Serializer\Encoder\XmlEncoder;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
use Symfony\Component\Serializer\Serializer;
/**
* Class SerializeService
* #package App\Service
*/
class SerializeService
{
/**
* #var Serializer
*/
private $serializer;
/**
* #var array
*/
private $encoders;
/**
* #var array
*/
private $normalizer;
/**
* SerializeService constructor.
*/
public function __construct()
{
$this->encoders = array(new XmlEncoder(), new JsonEncoder());
$this->normalizer = new ObjectNormalizer();
$this->normalizer->setCircularReferenceHandler(function ($object) {
return $object->getId();
});
$this->serializer = new Serializer($this->normalizer, $this->encoders);
}
public function serialize2Json($item)
{
return $this->serializer->serialize($item, 'json');
}
}
Then I get this error message:
Attempted to load class "SerializeService" from namespace "App\Service".
Did you forget a "use" statement for another namespace?
I've really tried to find solution for this and I have tried different options. If it is somewhere on stackoverflow please point me to this post.
Thanks in advance.

Answer 1

As Pib Ball said your autoloader is probably missing some infos.
I've tried the following setup
myProjectRoot/
app/
config/
Resources/
Service/
SerializeService.php <- your service file
I have used your code, no changes.
I have the same error as you, then I've edited my composer.json as following
................
"autoload": {
"psr-4": {
"": "src/",
"App\\": "app/",
}
},
Then executed the command composer update and then your service should be loaded.
Hope it may helps you