Unable to connect websocket java client on Heroku Node.js server

I'm trying to connect my Java client to Node.js server on Heroku via Jetty websockets, but there is no connection. @OnWebSocketConnect method doesn't execute.

    WebSocketClient client = new WebSocketClient();
    SimpleEchoSocket socket = new SimpleEchoSocket();

    try {
        client.start();
        URI echoUri = new URI(destUri);
        ClientUpgradeRequest request = new ClientUpgradeRequest();
        client.connect(socket, echoUri, request);
        socket.awaitClose(50, TimeUnit.SECONDS);
    } catch (Throwable t) {
        t.printStackTrace();
    } finally {
        try {
            client.stop();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }