abstract public boolean changePassword(String username,
    String oldpassword,
    String newpassword)

 abstract public String getHomeDirectory(String username) throws IOException

 public static NativeAuthenticationProvider getInstance() throws IOException 
{
        if (instance == null) {
            try {
                if (cls == null) {
                    throw new IOException(
                        "There is no authentication provider configured");
                }
                instance = (NativeAuthenticationProvider) cls.newInstance();
            } catch (Exception e) {
                throw new IOException(
                    "The authentication provider failed to initialize: " +
                    e.getMessage());
            }
        }
        return instance;
}

 abstract public  void logoffUser() throws IOException

 abstract public boolean logonUser(String username) throws IOException

 abstract public boolean logonUser(String username,
    String password) throws IOException, PasswordChangeException

 public static  void setProvider(Class cls) 
{
     
        try {
            if (ConfigurationLoader.isConfigurationAvailable(
                        PlatformConfiguration.class)) {
                cls = ConfigurationLoader.getExtensionClass(((PlatformConfiguration) ConfigurationLoader.getConfiguration(
                            PlatformConfiguration.class)).getNativeAuthenticationProvider());
                //
            }
        } catch (Exception e) {
            log.error("Failed to load native authentication provider", e);
            instance = null;
        }
        NativeAuthenticationProvider.cls = cls;
}