public void write(byte[] buf,int offset,int length,boolean isEnd) throws IOException {
  OutputStream os=_os;
  if (os != null) {
    os.write(buf,offset,length);
  }
}

public void write ( byte [ ] buf , int offset , int length , boolean isEnd ) throws IOException { OutputStream os = _os ; if ( os != null ) { os . write ( buf , offset , length ) ; } }
writes a buffer to the underlying stream .
