php中的捕获异常操作

<?phpif(!isset($_SESSION)){    session_start();}include '../common/mysql.class.php';include '../common/common_notice.php';try{    $arr=[];    $config=[];    $pdo=new Mysql($config);    $game_id=(int)(trim($_POST['game_id']));    $game_type=(int)$_POST['game_type'];    $uid=S_SESSION['uid'];    if(!$game_type){        throw new Exception(NOTICE_NUM_41,0);    }    if(!$game_id){        throw new Exception(NOTICE_NUM_37,0);    }    if(!$uid){        throw new Exception(NOTICE_NUM_40,0);    }    $collection_time=time();//游戏的收藏时间    $sql="INSERT INTO `ks_game_collection`(`game_id`,`collection_time`,`game_type`,`uid`) VALUES('$game_id', '$collection_time','$game_type','$uid')";    $rs=$pdo->doSql($sql);    if($rs>0){        $arr=['status'=>1,'notice_content'=>NOTICE_NUM_38];        exit(json_encode($arr,true));    }else{        throw new Exception(NOTICE_NUM_39,0);    }}catch(Exception $e){    $arr=['status'=>$e->getCode(),'notice_content'=>$e->getMessage()];    exit(json_encode($arr,true));}