code: public static void writeFile(BufferedInputStream reader,
  			BufferedOutputStream writer) throws IOException {
  		byte[] buff = new byte[8192];
  		int numChars;
  		while ((numChars = reader.read(buff, 0, buff.length)) != -1) {
  			writer.write(buff, 0, numChars);
  		}
  	}
docs: <p>
  copy reader into writer
  </p>
  
  @param reader
  @param writer
  @throws IOException