code: public void close() throws IOException {
                  if (channel != null && channel.isOpen()) {
                          channel.close();
                  }
  
                  buffer = null;
                  channel = null;
                  charBuffer = null;
                  decoder = null;
                  header = null;
          }
docs: Clean up all resources associated with this reader.<B>Highly
  recomended.</B>
  
  @throws java.io.IOException
  If an error occurs.