* 
     * @param serviceName
     *            JAAS configuration name
     */
    public JAASAuthenticator ( String serviceName ) {
        super(null);
        this.serviceName = serviceName;
    }


    /**
     * Create an authenticator using the given JAAS service and the specified credentials
     * 
     * @param serviceName
     *            JAAS configuration name
     * @param domain
     * @param username