title: Is Security Context Holder Thread Safe
body: <p>I am using spring security. I was wondering if in a filter I set </p>
  
  <p><code>SecurityContextHolder.getcontext().setAuthentication(null)</code> </p>
  
  <p>for one particular user who has at that instance suppose 100 api calls, would each of these calls securitycontextholder's authentication become null?</p>