android - 无法连接到 xmpp 服务器

Question

我尝试使用 xmpp 连接到 Gmail 服务器。它有效。但是当我尝试连接我的本地 xmpp 服务器时它不起作用。这是片段

// Create a connection
    SmackConfiguration.setPacketReplyTimeout(500);

    ConnectionConfiguration connConfig =
            new ConnectionConfiguration("ubuntu", 5222,"ubuntu");
    XMPPConnection connection = new XMPPConnection(connConfig);

    try {
        connection.connect();
        Log.i("XMPPClient", "[SettingsDialog] Connected to " + connection.getHost());
    } catch (XMPPException ex) {
        Log.e("XMPPClient", "[SettingsDialog] Failed to connect to " + connection.getHost());
        Log.e("XMPPClient", ex.toString());
        xmppClient.setConnection(null);
    }