title: Intercepting based on HTTP header in RESTeasy
body: <p>I am developing REST services with two types.</p>
  
  <ul>
  <li>before login no session token will be passed to HTTP header.</li>
  <li>after login session token will be passed in each request.</li>
  </ul>
  
  <p>I dont want to include @HeaderParam in each and every REST method. I want to intercept it first and based on that I want to check the validity of session. Please let me know </p>
  
  <ol>
  <li>how I can intercept based on headers in RESTEasy</li>
  <li>How to avoid intercepting few methods</li>
  </ol>
  
  <p>Thanks.</p>