RESTFUL形式 BaseException

use think\Exception;class BaseException extends Exception{    public $code = 400;    public $msg = '参数错误';    public $errorCode = 10000;    function __construct($params = [])    {        if (!is_array($params)) {            throw new Exception('参数必须是数组');            //return;        }        if (array_key_exists('code', $params)) {            $this->code = $params['code'];        }        if (array_key_exists('msg', $params)) {            $this->msg = $params['msg'];        }        if (array_key_exists('errorCode', $params)) {            $this->errorCode = $params['errorCode'];        }    }}