class DefaultValuesAuthenticationSourceDecorator implements
        AuthenticationSource, InitializingBean {

    public String getPrincipal() {
        String principal = target.getPrincipal();
        if (StringUtils.hasText(principal)) {
            return principal;
        } else {
            return defaultUser;
        }
    }

    public  DefaultValuesAuthenticationSourceDecorator();
    public  DefaultValuesAuthenticationSourceDecorator(
            AuthenticationSource target, String defaultUser,
            String defaultPassword);

}