title: Difference between Interceptors and Filters - Is this right?
body: <p>I'm researching this so that I can respond better in interviews. I've been searching around for a clear and concise answer. </p>
  
  <p>So far, and by all means correct me if I am wrong or lacking in detail: </p>
  
  <ol>
  <li>Filters are part of the Servlet API, Interceptors are Struts 2. (Seems obvious though) </li>
  <li>The Interceptor stack fires on requests in a configured package while filters only apply to their mapped URLs. </li>
  <li>Interceptors can be configured to execute or not depending on specific target action methods via excludeMethods and includeMethods while Filters lack this feature. </li>
  <li>Filters are an implementation of the Intercepting Filter pattern while Interceptors are of the Interceptor pattern. </li>
  </ol>
  
  <p>Does this seem like an accurate and complete answer? Should I add or correct anything?  What about threading issues / differences?</p>