如何修复Autoloader引发的Class Not Found错误？

错误信息 #

GET / - Uncaught Error: Class "App\Router" not found in /home/zumb/Documents/HHsite/ALPHA_VERSION/public/index.php:4
Stack trace:
#0 {main}
  thrown in /home/zumb/Documents/HHsite/ALPHA_VERSION/public/index.php on line 4

目录结构 #

• public
  • index.php
• src
  • Router.php
• vendor
  • altorouter
  • composer
  • autoload.php
• views
  • tableau.php
• composer.json
• composer.lock

相关代码 #

index.php #

<?php
require '../vendor/autoload.php';

$router = new App\Router(dirname(__DIR__) . DIRECTORY_SEPARATOR . 'views');
$router
    ->get('', 'tableau', '')
    ->get('/blog/category', 'category/show', 'category')
    ->run();

src/Router.php #

<?php
namespace App;

class Router {

    /**
     * @var string
     */
    private $viewPath;

    /**
     * @var AltoRouter
     */
    private $router;

    public function __construct(string $viewPath)
    {
        $this->viewPath =  $viewPath;
        $this->router = new \AltoRouter();
    }

    public function get(string $url, string $view, ?string $name = null)
    {
        $this->router->map('GET', $url, $view, $name);
        return $this;
    }

    public function run()
    {
        print "hey";
        $match = $this->router->match();
        $view = $match['target'];
        ob_start();
        require $this->viewPath . DIRECTORY_SEPARATOR . $view . '.php';
        $content = ob_get_clean();
        require $this->viewPath . DIRECTORY_SEPARATOR . 'layouts/default.php';

        return $this;
    }
}

composer.json #

{
    "autoload": {
        "psr-4": {
            "App\\": "src/"
        }
    },
    "require": {
        "altorouter/altorouter": "^2.0"
    }
}

修复步骤 #

1. 使用绝对路径引入autoload.php
   替换index.php中的相对路径引入，避免环境路径差异导致的问题：

   require __DIR__ . '/../vendor/autoload.php';
   

2. 重新生成优化版自动加载映射
   执行以下命令，强制Composer重新生成并优化类映射文件：

   composer dump-autoload -o
   

3. 检查文件名大小写（Linux/macOS环境）
   确认src目录下的文件名为Router.php（首字母大写），Linux和macOS系统严格区分文件名大小写，若文件名为小写router.php会导致PSR-4自动加载无法匹配。

4. 验证Composer自动加载配置
   打开vendor/composer/autoload_psr4.php，确认存在以下配置项：

   'App\\' => array($baseDir . '/src'),
   

   若不存在，执行composer install重新安装依赖并生成自动加载文件。

内容的提问来源于stack exchange，提问作者zumb