code: public String getRealPath(String path) {
  
          if (defaultExternalContext != null) {
              return defaultExternalContext.getRealPath(path);
          }
  
          throw new UnsupportedOperationException();
  
      }
docs: <p class="changed_added_2_0">Returns a String containing the real
  path for a given virtual path. </p>
  
  <div class="changed_added_2_0">
  
  <p><em>Servlet:</em> This must be the value returned by the
  <code>javax.servlet.ServletContext</code> method
  <code>getRealPath()</code>.</p>
  
  <p>The default implementation throws
  <code>UnsupportedOperationException</code> and is provided
  for the sole purpose of not breaking existing applications that extend
  this class.</p>
  
  </div>
  
  @param path The context of the requested initialization parameter
  
  @since 2.0