code: public void resetBuffer()
          throws IllegalStateException
      {
          // Shutdown filters without observation
          
          if (_out!=null && _out!=_realOut)
          {
              ArrayList save_observers=_observers;
              _observers=null;
              _nulled=true;
              try
              {
                  // discard current buffer and set it to output
                  if (_bufferedOut!=null)    
                  {
                      _bufferedOut.resetStream();
                      if (_bufferedOut instanceof ChunkingOutputStream)
                          ((ChunkingOutputStream)_bufferedOut).setChunking(false);
                  }
              }
              catch(Exception e)
              {
                  LogSupport.ignore(log,e);
              }
              finally
              {
                  _observers=save_observers;
              }
          }
          _contentLength=-1;
          _nulled=false;
  	    _bytes=0;
          _written=false;
          _out=_realOut;
          try
          {
              notify(OutputObserver.__RESET_BUFFER);
          }
          catch(IOException e)
          {
              LogSupport.ignore(log,e);
          }
      }
docs: Reset Buffered output.
  If no data has been committed, the buffer output is discarded and
  the filters may be reinitialized.
  @exception IllegalStateException