> For the complete documentation index, see [llms.txt](https://sofa.k43.ch/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sofa.k43.ch/hints-and-tips/faq.md).

# FAQ

#### **Q: How should I use this class?**

* You need to first instantiate a SOFA object with the authorization server and the authorization scope.
* The application then calls the appropriate `authenticateWithXxx()` method based on the desired OAuth 2.0 authentication method (grant type).
* From then on, the application can get a valid access token anytime thru `getAccessToken()` or a ready-to-use HTTP authorization header with `getHttpAuthorizationHeader()`. If the access token has expired in the meantime, SOFA will transparently call the authorization server again for a refreshed or a new token based on the used grant type.
* The HTTP authorization header with the access token must then be added to each HTTP request sent to the server holding the protected resource.

#### **Q: Does SOFA need any additional library or jar files?**

* Only one additional library (`org.json.JSONObject`) is used to parse the returned JSON data from the authorization server. The required class is included in the distribution package.

#### **Q: Is SOFA affected by the Apache Log4j vulnerability?**

* No, SOFA uses the standard Java Logger class which was not affected by this vulnerability. 

#### Q: How can I get support?

* Support is provided on best-effort basis. You may contact the author thru email at <andy.brunner@k43.ch>. Please describe your problem as detailed as possible and include the [debugging](/quick-start/logging-debugging.md) log whenever possible. Note that the log does not include any confidential data.