title: Get/set ServletRequest attributes from ActionContext
body: <p>I need to set a <code>ServletRequest</code> attribute within a Struts2 interceptor (not action class).</p>
  <p>Does the <code>ActionContext</code> expose a <code>Map&lt;String, Object&gt;</code> to control request attributes, like it does for session attributes?</p>
  <p>I see <code>ActionContext</code> implements a map. Is the <code>ActionContext</code> itself a wrapper for the request attributes?</p>