title: Change Response in Oauth2 Spring
body: <p>Hi i have posted this question in this forum. 
  I post it here too, to have more chance for a response</p>
  
  <p><a href="http://forum.spring.io/forum/spring-projects/security/oauth/745627-response-of-oauth2" rel="nofollow">http://forum.spring.io/forum/spring-projects/security/oauth/745627-response-of-oauth2</a></p>
  
  <p>I need to add information in the json response of an Oauth authentication2. Now my configuration return a response like:</p>
  
  <pre><code>{"access_token":"523dd467-e5c0-407b-95e4-ea60a403d772",
  "token_type":"bearer",
  "refresh_token ":"e3378c95-1ebf-419b-bf45-e734d8e94aba",
  "expires_in":43199}
  </code></pre>
  
  <p>But what i wish is to have is evriting like:</p>
  
  <pre><code>{"access_token":"523dd467-e5c0-407b-95e4-ea60a403d772",
  "token_type":"bearer",
  "refresh_token ":"e3378c95-1ebf-419b-bf45-e734d8e94aba",
  "expires_in":43199, "other":"value"}
  </code></pre>
  
  <p>Is this possible in a easy way?</p>
  
  <p>Other question is:
  It's correct that if I wish to change the expireTime i should implement the TokenStore interface?
  Is there any documentation about it?</p>
  
  <p>The last question is:
  Is there a easy way to make Oauth2 authentication with Credentials (Username and Password) in json format?</p>