我按照老师方法

class ExceptionHandler extends Handle{

    private $code;

    private $msg;

    private $errorCode;

    //需要返回客户端当前请求的URL路径

    public function render(\Exception $e){

        dump($e);

        if($e instanceof BaseException){

            //如果是自定义的异常

            $this->code = $e->code;

            $this->msg  = $e->msg;

            $this->errorCode = $e->errorCode;

        }else{

            //系统异常

            $this->code = 500;

            $this->msg  = '系统内部错误';

            $this->errorCode = 999;

        }

        $request = Request::instance();

        $result = [

            'msg' => $this->msg,

            'error_code' => $this->errorCode,

            'request_url'=> $request->url()

        ];

        return json($result, $code);

    }

}

打印出来 是下面的情况 是什么问题？？？

object(think\exception\ErrorException)#12 (9) {
 ["severity":protected] => int(64)
 ["data":protected] => array(0) {
 }
 ["message":protected] => string(112) "Access level to app\lib\exception\BaseException::$code must be protected (as in class think\Exception) or weaker"
 ["string":"Exception":private] => string(0) ""
 ["code":protected] => int(0)
 ["file":protected] => string(69) "/www/web/disc/public_html/application/lib/exception/BaseException.php"
 ["line":protected] => int(12)
 ["trace":"Exception":private] => array(1) {
   [0] => array(4) {
     ["function"] => string(11) "appShutdown"
     ["class"] => string(11) "think\Error"
     ["type"] => string(2) "::"
     ["args"] => array(0) {
     }
   }
 }
 ["previous":"Exception":private] => NULL
}