php依赖注入原理的代码实现

namespace Database;

use ReflectionMethod;

class Database
{

    protected $adapter;

    public function __construct ()
    {

    }

    public function test (MysqlAdapter $adapter)
    {
         $adapter->test();
    }
}

class MysqlAdapter
{

    public function test ()
    {
    	echo 'i am MysqlAdapter test';
    }
}

class App
{
    public static function run ($instance, $method)
    {
        if (! method_exists($instance, $method)) {
            return null;
        }

        $reflector = new ReflectionMethod($instance, $method);

        $parameters = [1];

        foreach ($reflector->getParameters() as $key => $parameter) {
          
          $class = $parameter->getClass();

          if ($class) {
              array_splice($parameters, $key, 0, [new $class->name()]);
          }
        }

        call_user_func_array([$instance,$method], $parameters);
    }
}

App::run(new Database(), 'test');