title: spring rest api versioning
body: <p>In my spring controller, I have 2 rest api methods. example: getUser, getRole
  One client is accessing it by like "/api/v1".
  Now I want to update one of the methods. i.e., getRole. So the new method/version will be "/api/v2".
  But no change in methods of v1. i.e., "/api/v1".</p>
  
  <p>How to handle the rest methods with both versions in the same project ?
  I mean, getUser rest API should support both "/api/v1" and "/api/v2". 
  And getRole rest API should support both versions but different functionality (example: database changed, logic changed). 
  In simple words, 
  1. getUser will have 1 method which supports both versions.
  2. getRole will have 2 methods for each versions.</p>
  
  <p>Please help me here.</p>