code: private void copy(InputStream is, OutputStream os) throws IOException {
  		byte[] buffer = new byte[bufferSize];
  		int nRead;
  		while((nRead = is.read(buffer)) != -1) {
  			os.write(buffer, 0, nRead);
  		}
  		os.flush();
  	}
docs: <p>Reads data from the <code>InputStream</code> and writes it to the <code>OutputStream</code>.</p>
  @param is the input stream
  @param os the output stream
  @throws IOException