<?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()";
  }
}