@nimakro @edvin I used OAuth2 in a JavaFX client to get at the Dropbox API. The web browser is important because that's where the user logs into the target service (ex Dropbox) using their account info. It's not simply "make a call, get a token".
In this JavaFX app,
1. Beforehand, register the app with the service (ex, my JavaFX client registered at Dropbox)
2. The user opens a browser and navigates to a special URL
3. The user logs into dropbox and get an access token
4. (my impl) The user pastes the token from the web page into a JavaFX textfield
5. The Dropbox authorization is finished in the JavaFX client and an access token is retrieved
6. The access token is used in subsequent calls