On the Javadocs for DbxWebAuth it says access tokens are valid for years:
|
* remains valid for years. |
However the official documentation reads:
Dropbox access tokens are short lived, and will expire after a short period of time. The exact expiry time of a token is returned by the token endpoint (or the redirect URI in implicit grant) - but is generally long enough for a reasonable web session.
From: https://developers.dropbox.com/oauth-guide