title: why are struts Action classes not thread safe?
body: <p>I can read in many websites that Struts Action classes are not thread safe . I am not able to understand why this is so .</p>
  
  <p>Also I read a book which says <strong>"Struts action classes are cached and reused for performance 
  optimization at the cost of having to implement the action classes in a thread-safe manner"</strong></p>
  
  <p>how is caching action classes and being thread safe related? .</p>