PSR4-在composer中使用自动加载而不是require

我是SLIM3的新手,被跟踪 a tutorial autoload require ,这是我的文件结构:

dev
|── composer.json
|── index.php
|──── classes
|──── vendor

这是我的 composer.json

{
    "require": {
        "slim/slim": "^3.0",
        "monolog/monolog": "^1.23"
    },
    "autoload": {
        "psr-4": {
            "": "classes/"
        }
    }
}

这是 pdf.class.php 坐在下面 classes

dev
|── composer.json
|── index.php
|──── classes
     |─ pdf.class.php
|──── vendor

class pdfClass {
    public function testme(){
        return 'i am working';
        $this->logger->addInfo("Something interesting happened");
    }
}

<?php
use \Psr\Http\Message\ServerRequestInterface as Request;
use \Psr\Http\Message\ResponseInterface as Response;

// Require for loading the vendor libraries installed by composer
require 'vendor/autoload.php';
// require 'classes/pdf.class.php'; // << If I uncomment this line it works.


$config['displayErrorDetails'] = true;
$config['addContentLengthHeader'] = false;

$app = new \Slim\App(["settings" => $config]);
$container = $app->getContainer();

$app->post('/{controller}/{function}', function (Request $request, Response $response) {
    $headers = $request->getHeaders();
    $params = $request->getParsedBody();

    $classname = $request->getAttribute('controller').'Class';

    $controller = new $classname;
    $function = $request->getAttribute('function');

    $result = $controller->$function();

    $response->getBody()->write($result);
    return $response;
});

$app->run();

难道不是吗 自动加载 创作者json