}

    /**
     * SSO logout endpoint.
     *
     * This method handles SSO logout requests, coordinating with the SSO provider
     * to properly terminate the user's SSO session. It may involve redirecting
     * to the SSO provider's logout endpoint or performing local logout operations.
     *
     * @return ActionResponse directing to the logout page or SSO provider logout endpoint
     */
    @Execute

     * @return The action response.
     */
    ActionResponse getResponse(SsoResponseType responseType);

    /**
     * Performs logout for the specified user.
     * @param user The user to logout.
     * @return The logout URL or null if not applicable.
     */
    String logout(FessUserBean user);

    }

    @Test
    public void test_nullSafeLogout() {
        SpnegoAuthenticator authenticator = new SpnegoAuthenticator();

        // SPNEGO logout should return null (relies on Kerberos infrastructure)
        String logoutUrl = authenticator.logout(null);
        assertNull(logoutUrl);
    }

    @Test
    public void test_nullSafeGetResponse() {

            }
        }
        return null;
    }

    /**
     * Performs logout operations for the specified user using SSO.
     *
     * @param user The user to logout
     * @return The logout URL from the SSO authenticator, or null if SSO is not available
     */
    public String logout(final FessUserBean user) {
        if (available()) {

        activityHelper.useEcsFormat = false;
        activityHelper.logout(OptionalThing.empty());
        assertEquals("action:LOGOUT\tuser:-\tpermissions:-", localLogMsg.get());

        activityHelper.logout(createUser("testuser", new String[0]));
        assertEquals("action:LOGOUT\tuser:testuser\tpermissions:-", localLogMsg.get());

        activityHelper.logout(createUser("testuser", new String[] { "111", "222" }));

 *
 * # Assertion Consumer Service URL
 * saml.sp.assertion_consumer_service.url=https://your-fess-server.example.com/sso/
 *
 * # Single Logout Service URL
 * saml.sp.single_logout_service.url=https://your-fess-server.example.com/sso/logout
 * </pre>
 *
 * <h2>Complete Configuration Example (Okta)</h2>
 * <pre>
 * sso.type=saml
 *
 * # IdP settings from Okta SAML setup instructions

		redirectPage.append("/error/systemerror/");
		response.sendRedirect(redirectPage.toString());
	} else {
		response.sendError(statusCode);
	}
} else if("logOut".equals(type)) {
	redirectPage.append("/login/?type=logout&code=" + statusCode);
	response.sendRedirect(redirectPage.toString());
} else if("badRequest".equals(type)) {
	redirectPage.append("/error/badrequest/");

		redirectPage.append("/error/systemerror/");
		response.sendRedirect(redirectPage.toString());
	} else {
		response.sendError(statusCode);
	}
} else if("logOut".equals(type)) {
	redirectPage.append("/login/?type=logout&code=" + statusCode);
	response.sendRedirect(redirectPage.toString());
} else if("badRequest".equals(type)) {
	redirectPage.append("/error/badrequest/");

            }
        });
        log(valueMap);
    }

    /**
     * Log the logout activity.
     * @param user The user.
     */
    public void logout(final OptionalThing<FessUserBean> user) {
        final Map<String, String> valueMap = new LinkedHashMap<>();
        valueMap.put("action", Action.LOGOUT.name());
        valueMap.put("user", user.map(FessUserBean::getUserId).orElse("-"));

    <error-code>403</error-code>
    <location>/WEB-INF/view/error/redirect.jsp?type=logOut</location>
  </error-page>
  <error-page>
    <error-code>404</error-code>
    <location>/WEB-INF/view/error/redirect.jsp?type=notFound</location>
  </error-page>
  <error-page>
    <error-code>408</error-code>
    <location>/WEB-INF/view/error/redirect.jsp?type=logOut</location>
  </error-page>
  <error-page>
    <error-code>429</error-code>