title: How to migrate OAuth1 token/secret pairs to OAuth2 access tokens for the Dropbox API?
body: <p>If a user has already authorized our app for OAuth 1 (so we have a valid token/secret pair for this user), is it possible to get a valid OAuth 2.0 access token without the user having to explicitly re-authorize our app again? I know that some APIs support this (e.g. Soundcloud and I think also Google), but I haven't found anything related to OAuth token migration in the Dropbox API documentation.</p>
  
  <p>Context: We have an application in Java that accesses the Dropbox API with OAuth 1.0a using the Scribe OAuth library and want to migrate to the official Dropbox Java API that only supports OAuth 2 (and we don't want to have all our users having to re-authorize us).</p>