think\Debug::inject PHP Method

    public static function inject(Response $response, &$content)
    {
        $config = Config::get('trace');
        $type = isset($config['type']) ? $config['type'] : 'Html';
        $request = Request::instance();
        $class = false !== strpos($type, '\\') ? $type : '\\think\\debug\\' . ucwords($type);
        unset($config['type']);
        if (class_exists($class)) {
            $trace = new $class($config);
        } else {
            throw new ClassNotFoundException('class not exists:' . $class, $class);
        }
        if ($response instanceof Redirect) {
            //TODO 记录
        } else {
            $output = $trace->output($response, Log::getLog());
            if (is_string($output)) {
                // trace调试信息注入
                $pos = strripos($content, '</body>');
                if (false !== $pos) {
                    $content = substr($content, 0, $pos) . $output . substr($content, $pos);
                } else {
                    $content = $content . $output;
                }
            }
        }
    }

 /**
  * 执行应用程序
  * @access public
  * @param Request $request Request对象
  * @return Response
  * @throws Exception
  */
 public static function run(Request $request = null)
 {
     is_null($request) && ($request = Request::instance());
     if ('ico' == $request->ext()) {
         throw new HttpException(404, 'ico file not exists');
     }
     $config = self::initCommon();
     try {
         // 开启多语言机制
         if ($config['lang_switch_on']) {
             // 获取当前语言
             $request->langset(Lang::detect());
             // 加载系统语言包
             Lang::load(THINK_PATH . 'lang' . DS . $request->langset() . EXT);
             if (!$config['app_multi_module']) {
                 Lang::load(APP_PATH . 'lang' . DS . $request->langset() . EXT);
             }
         }
         // 获取应用调度信息
         $dispatch = self::$dispatch;
         if (empty($dispatch)) {
             // 进行URL路由检测
             $dispatch = self::routeCheck($request, $config);
         }
         // 记录当前调度信息
         $request->dispatch($dispatch);
         // 记录路由信息
         self::$debug && Log::record('[ ROUTE ] ' . var_export($dispatch, true), 'info');
         // 监听app_begin
         Hook::listen('app_begin', $dispatch);
         switch ($dispatch['type']) {
             case 'redirect':
                 // 执行重定向跳转
                 $data = Response::create($dispatch['url'], 'redirect')->code($dispatch['status']);
                 break;
             case 'module':
                 // 模块/控制器/操作
                 $data = self::module($dispatch['module'], $config, isset($dispatch['convert']) ? $dispatch['convert'] : null);
                 break;
             case 'controller':
                 // 执行控制器操作
                 $data = Loader::action($dispatch['controller'], $dispatch['params']);
                 break;
             case 'method':
                 // 执行回调方法
                 $data = self::invokeMethod($dispatch['method'], $dispatch['params']);
                 break;
             case 'function':
                 // 执行闭包
                 $data = self::invokeFunction($dispatch['function'], $dispatch['params']);
                 break;
             case 'response':
                 $data = $dispatch['response'];
                 break;
             default:
                 throw new \InvalidArgumentException('dispatch type not support');
         }
     } catch (HttpResponseException $exception) {
         $data = $exception->getResponse();
     }
     // 清空类的实例化
     Loader::clearInstance();
     // 输出数据到客户端
     if ($data instanceof Response) {
         $response = $data;
     } elseif (!is_null($data)) {
         // 默认自动识别响应输出类型
         $isAjax = $request->isAjax();
         $type = $isAjax ? Config::get('default_ajax_return') : Config::get('default_return_type');
         $response = Response::create($data, $type);
     } else {
         $response = Response::create();
     }
     // 监听app_end
     Hook::listen('app_end', $response);
     // Trace调试注入
     if (Config::get('app_trace')) {
         Debug::inject($response);
     }
     return $response;
 }