<?php
class Application{
    public static function main(){
        header("content-type:text/html;charset=utf-8");
        self::register();
        self::router();
    }
    public static function register(){
        spl_autoload_register("self::loadClass");
    }
    public static function loadClass($class){
        $class=str_replace('\\', '/', $class);
        $class="./".$class.".php";
        require_once $class;        
    }
    public static function router(){
        if(isset($_SERVER['PATH_INFO'])){
            $pathinfo=array_filter(explode("/", $_SERVER['PATH_INFO']));
            for($i=1;$i<=count($pathinfo);$i++){
                $key=isset($pathinfo[$i]) ? $pathinfo[$i] : '';
                $value=isset($pathinfo[$i+1]) ? $pathinfo[$i+1] :"";
                switch ($i) {
                    case 1:
                        $_GET['m']=ucfirst($key);
                        break;
                    case 2:
                        $_GET['c']=ucfirst($key);
                        break;
                    case 3:
                        $_GET['a']=$key;
                        break;
                    default:
                        if($i>3){
                            if($i%2==0){
                                $_GET[$key]=$value;
                            }
                        }
                        break;
                }
            }
        }
        $_GET['m']=!empty($_GET['m']) ? ucfirst($_GET['m']) : 'Index';
        $_GET['c']=!empty($_GET['c']) ? ucfirst($_GET['c']) : 'Index';
        $_GET['a']=!empty($_GET['a']) ? $_GET['a'] : 'index';
        $class="\\Controller\\{$_GET['m']}\\{$_GET['c']}";
        $controller=new $class;
        $controller->$_GET['a']();
    }
}

Application::main();

<?php
namespace Controller\Index;

use Service\User;
class Index{
    public function __construct(){
        echo "构造方法<br/>";
    }
    public function index(){
        new User();
        print_r($_GET);
    }
    public function login(){
        echo "login()";
    }
}