@Override
    public void stop() {
        CertificateManager.removeListener(this);
        stopListeners();
        super.stop();
    }
Sets the TCP port on which a listener accepts connections.

@param type The connection type for which a listener is to be configured.
@param startInDirectTlsMode true when the listener to be configured is in Direct TLS mode, otherwise false.
@param port a port number.
xmppserver/src/main/java/org/jivesoftware/openfire/spi/ConnectionManagerImpl.java