新手问题，无法连接WebSocket connection to 'ws://127.0.0.1:8282/' failed:

<button class="ttt">2122</button>
    <script src="/static/js/jquery.min.js"></script>
    <script>
       ws = new WebSocket('ws://127.0.0.1:8282');

       $('.ttt').click(function () { 
            ws.send('2222')
        })
    </script>

public static function onConnect($client_id)
    {
        // // 向当前client_id发送数据 
        // Gateway::sendToClient($client_id, "Hello $client_id\r\n");
        // // 向所有人发送
        // Gateway::sendToAll("$client_id login\r\n");
        echo "$client_id 你好";
    }